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Electronics, sensors, robotics kits, PC components, peripherals — everything Unik Systems carries, in one place.
Keltron 3300uF 25V Radial Electrolytic Capacitor High Performance Capacitor
[Through Hole Capacitor] The Keltron 3300uF 25V Electrolytic Capacitor is a high-performance aluminum electrolytic capacitor designed for energy storage, voltage filtering, and ripple suppression applications. It is widely used in power supply circuits, audio amplifiers, inverter systems, battery chargers, and industrial electronics. In addition, the capacitor provides excellent filtering capability by reducing voltage fluctuations and unwanted electrical noise. As a result, it helps improve circuit stability and enhances overall system performance. Because of its 3300uF high capacitance value, the capacitor is ideal for smoothing DC power rails and handling transient current demands. Furthermore, the 25V DC voltage rating makes it suitable for a variety of low-voltage electronic applications. The radial lead design allows easy PCB installation and secure mounting. Moreover, Keltron capacitors are known for their dependable quality, stable electrical characteristics, and long operational life. This capacitor is commonly used in audio amplifier power supplies, SMPS circuits, LED power supplies, inverter systems, battery chargers, and DIY electronics projects. 🔹 Key Features Genuine Keltron capacitor High capacitance 3300uF value Rated voltage of 25V DC Excellent ripple filtering performance Suitable for audio and power supply circuits Low leakage current Long operational life Radial lead through-hole design Reliable and stable performance 🔹 Technical Specifications Brand: Keltron Product Type: Electrolytic Capacitor Capacitor Type: Aluminum Electrolytic Capacitance: 3300uF Rated Voltage: 25V DC Tolerance: ±20% Mounting Type: Through-Hole (Radial Lead) Polarized: Yes Lead Type: Radial Operating Temperature: Up to 105°C (Series Dependent) Application: Filtering, Decoupling, Energy Storage 🔹 Applications This capacitor is suitable for: Audio amplifier circuits Power supply filtering SMPS circuits Inverter systems Battery chargers LED driver circuits Industrial electronics DIY electronics projects Electronic repair applications 🔹 Package Includes 1 × Keltron 3300uF 25V Radial Electrolytic Capacitor
16mm Ultrasonic Humidifier Atomizer Disc Piezoelectric Mist Maker Transducer Module 108KHz
[Ultrasonic Sensor] The 16mm Ultrasonic Humidifier Atomization Module is a high-efficiency piezoelectric transducer designed for mist generation and humidification applications. It operates using ultrasonic vibration technology to convert water into ultra-fine mist particles quickly and efficiently. In addition, the module works on the principle of ultrasonic cavitation, where high-frequency sound waves generate rapid compression and rarefaction inside the water. As a result, microscopic water droplets are released into the air as cool mist. Because of its 108KHz resonant frequency, the atomizer produces fine and uniform fog particles while maintaining low noise operation. Furthermore, the compact 16mm design allows easy integration into humidifiers, aroma diffusers, medical atomizers, and DIY mist generation systems. The atomization disc is built using durable piezoelectric material for long operational life and stable performance. Moreover, the module consumes very little power while providing efficient mist output. ⚠️ Note: This atomizer module requires a compatible ultrasonic driver board for operation. The driver circuit is not included in the package and must be purchased separately. This ultrasonic humidifier module is widely used in humidifiers, beauty care devices, medical atomization equipment, aroma diffusers, and DIY electronics projects. 🔹 Key Features 16mm ultrasonic atomizer disc High-frequency 108KHz operation Fine and uniform mist generation Low noise operation Small fog particle output Long operational life High stability performance Low power consumption Suitable for humidifier and mist maker projects 🔹 Technical Specifications Product Type: Ultrasonic Atomizer Transducer Module Atomizer Diameter: 16mm Operating Voltage: DC 3.7V –5V Resonant Frequency: 108KHz Resonant Impedance: < 2 Ohms Coupling Factor: > 52% Electrostatic Capacity: 3000pF Spray Quantity: > 110mL/h Operation Type: Ultrasonic Piezoelectric Atomization Fog Particle Type: Ultra-Fine Mist Noise Level: Low Noise Operation Material: Piezoelectric Ceramic + Metal 🔹 Working Principle The ultrasonic atomizer uses a piezoelectric transducer immersed in water. When driven at high frequency, the transducer creates rapid mechanical oscillations that generate cavitation bubbles and surface waves. Consequently, microscopic water droplets are released into the air as cool mist with minimal energy consumption. 🔹 Applications This ultrasonic atomizer module is suitable for many applications, including: Humidifiers Mist makers Aroma diffusers Medical atomizers Facial beauty equipment DIY humidification projects Decorative fog systems 🔹 Package Includes 1 × 16mm Ultrasonic Humidifier Atomization Sensor Module
2200uf / 16v Electrolytic Capacitor Keltron
[Through Hole Capacitor] Electrolytic decoupling capacitors 2200uF / 16V. These capacitors are great transient/surge suppressors and work well in high-voltage and audio applications. High-quality radial electrolytic capacitors. Specifications: Value: 2200uF Rated Voltage: 16V Package Content: 1x Keltron capacitor 2200uF/16v
DC 12V 300RPM Gear Motor Centre Shaft DC Geared Motor Heavy Duty Motor for Robotics
[Gear Motor] Description: This 12V 300RPM Gear Motor can be used for heavy-duty applications, robotics, or any industrial or educational applications. It has a wide range of features for obtaining the optimal performance characteristics. 12V 300RPM Gear Motor is very easy to use and does not need expensive motor control circuitry. The 12V 300RPM Gear Motor are very popularly used in robotics applications. The gearbox of the motor helps in providing greater torque that is required to drive robotic vehicles. Based on the gearbox design the RPM and Torque of the motor will vary. Specifications: Working Voltage: 12V DC Rated RPM: 300RPM Load Current Max: 300mA No-Load Current: 60mA Torque Range: 5kg-cm (Approx) Stall torque: 28kg-cm (Approx) Features: 12V 300RPM Gear Motor comes with good-quality gear. The gearbox is sealed and lubricated with lithium grease and requires no maintenance. Although the motor gives 300 RPM at 12V, the motor runs smoothly from 4V to 12V and gives a wide range of RPM, and torque. The shaft has a hole for better coupling. Package Included: 1 x 12V 300RPM Gear Motor Centre Shaft DC Geared Motor Heavy Duty Motor for Robotics
220uf / 25v Electrolytic Capacitor-Keltron
[Through Hole Capacitor] The KELTRON 220uF 25V Electrolytic Capacitor is a high-quality aluminum electrolytic capacitor designed for filtering, coupling, decoupling, and energy storage applications in electronic circuits. It is widely used in power supplies, audio amplifiers, control circuits, and industrial electronic equipment. In addition, the capacitor effectively smooths DC voltage and suppresses unwanted electrical noise. As a result, it helps improve circuit stability and overall system performance. Because of its 220uF capacitance value, the capacitor provides reliable energy storage and transient suppression for low-voltage electronic circuits. Furthermore, the 25V DC rating makes it suitable for various power supply and signal processing applications. The radial lead design allows easy PCB installation and secure mounting. Moreover, KELTRON capacitors are known for their dependable performance, long operational life, and stable electrical characteristics. This capacitor is commonly used in audio amplifiers, SMPS power supplies, battery chargers, LED drivers, inverter circuits, and DIY electronics projects. 🔹 Key Features Genuine KELTRON capacitor High-quality aluminum electrolytic construction 220uF capacitance value 25V DC rated voltage Excellent filtering and decoupling performance Low leakage current Long operational life Easy PCB mounting Suitable for power supply and audio applications 🔹 Technical Specifications Brand: KELTRON Product Type: Electrolytic Capacitor Capacitor Type: Aluminum Electrolytic Capacitance: 220uF Rated Voltage: 25V DC Tolerance: ±20% Mounting Type: Through-Hole (Radial Lead) Polarized: Yes Lead Type: Radial Operating Temperature: Up to 105°C (Series Dependent) Application: Filtering, Decoupling, Energy Storage 🔹 Applications This capacitor is suitable for: Power supply filtering Audio amplifier circuits SMPS power supplies LED driver circuits Battery chargers Inverter circuits Industrial electronics DIY electronics projects Electronic repair applications 🔹 Package Includes 1 × KELTRON 220uF 25V Electrolytic Capacitor
4700uf / 35v Electrolytic Capacitor-Keltron
[Through Hole Capacitor] Electrolytic decoupling capacitors 4700uF / 35V. These capacitors are great transient/surge suppressors and work well in high-voltage and audio applications. High-quality radial electrolytic capacitors. Specifications: Value: 4700uF Rated Voltage: 35V Package Content: 1x capacitor
470uF 25V Radial Electrolytic Capacitor High Performance Capacitor KELTRON
[Through Hole Capacitor] The KELTRON 470uF 25V Electrolytic Capacitor is a reliable aluminum electrolytic capacitor designed for filtering, energy storage, and decoupling applications in electronic circuits. It is commonly used in power supplies, audio equipment, control circuits, and electronic repair work. In addition, the capacitor helps smooth voltage fluctuations and suppress unwanted electrical noise. As a result, it improves circuit stability and enhances the performance of electronic devices. Because of its 470uF capacitance value, the capacitor provides effective filtering for DC power rails and transient suppression applications. Furthermore, the 25V voltage rating makes it suitable for low-voltage power supplies, amplifier circuits, and embedded electronics projects. The radial lead design allows convenient PCB installation and secure mounting. Moreover, the high-quality aluminum electrolytic construction offers dependable performance and long service life. This capacitor is widely used in audio amplifiers, SMPS circuits, LED drivers, battery chargers, Arduino projects, and industrial electronic equipment. 🔹 Key Features High-quality aluminum electrolytic capacitor 470uF capacitance value 25V DC voltage rating Excellent filtering and decoupling performance Helps reduce voltage ripple and noise Suitable for audio and power supply applications Radial lead through-hole design Reliable long operational life Easy PCB installation 🔹 Technical Specifications Product Type: Electrolytic Capacitor Capacitor Type: Aluminum Electrolytic Capacitance: 470uF Rated Voltage: 25V DC Tolerance: ±20% Mounting Type: Through-Hole (Radial Lead) Polarized: Yes Operating Temperature: -40°C to +105°C (varies by series) Lead Type: Radial Leads Application: Filtering, Decoupling, Energy Storage 🔹 Applications This capacitor is suitable for: Power supply filtering Audio amplifier circuits SMPS power supplies LED driver circuits Battery chargers DC voltage smoothing Arduino and microcontroller projects Industrial electronics Electronic repair applications 🔹 Package Includes 1 × 470uF 25V Radial Electrolytic Capacitor
1000uf / 16V KELTRON High Quality Electrolytic Capacitor
[Through Hole Capacitor] Electrolytic decoupling capacitors 1000uF / 16V by KELTRON . These capacitors are great transient/surge suppressors and work well in high-voltage and audio applications. High-quality radial electrolytic capacitors. Specifications: Value: 1000uF Rated Voltage: 16V Package Content: 1x 1000uf / 16v KELTRON High Quality Electrolytic Capacitor *Image might be different.
1000uf / 25v KELTRON High Quality Electrolytic Capacitor
[Basic Electronic Components, Capacitors, Electronic Components] Electrolytic decoupling capacitors 1000uF / 25V by KELTRON . These capacitors are great transient/surge suppressors and work well in high-voltage and audio applications. High-quality radial electrolytic capacitors. Specifications: Value: 1000uF Rated Voltage: 25V Package Content: 1x 1000uf / 25v KELTRON High Quality Electrolytic Capacitor *Image might be different.
Out of stock22uf / 25v Electrolytic Capacitor
[Through Hole Capacitor] Electrolytic decoupling capacitors 22uF / 25V. These capacitors are great transient/surge suppressors and work well in high-voltage and audio applications. High-quality radial electrolytic capacitors. Specifications: Value: 22uF Rated Voltage: 25V Package Content: 1x capacitor *Image might be different.
4.7uf / 63v Electrolytic Capacitor Keltron
[Through Hole Capacitor] Electrolytic decoupling capacitors 4.7uF / 63V. These capacitors are great transient/surge suppressors and work well in high-voltage and audio applications. High-quality radial electrolytic capacitors. Specifications: Value: 4.7uF Rated Voltage: 63V Package Content: 1x capacitor
47uf / 63v Electrolytic Capacitor
[Through Hole Capacitor] Electrolytic decoupling capacitors 47uF / 63V. These capacitors are great transient/surge suppressors and work well in high-voltage and audio applications. High-quality radial electrolytic capacitors. Specifications: Value: 47uF Rated Voltage: 63V Package Content: 1x capacitor
DC 12V 1000RPM Gear Motor Centre Shaft DC Geared Motor Heavy Duty Motor for Robotics
[Gear Motor] Description: This 12V 1000RPM Gear Motor can be used for heavy-duty applications, robotics, or any industrial or educational applications. It has a wide range of features for obtaining the optimal performance characteristics. 12V 1000RPM Gear Motor is very easy to use and does not need expensive motor control circuitry. The 12V 1000RPM Gear Motor are very popularly used in robotics applications. The gearbox of the motor helps in providing greater torque that is required to drive robotic vehicles. Based on the gearbox design the RPM and Torque of the motor will vary. Specifications: Working Voltage: 12V DC Rated RPM: 1000RPM Load Current Max: 300mA No-Load Current: 60mA Torque Range: 5kg-cm (Approx) Stall torque: 28kg-cm (Approx) Features: 12V 1000RPM Gear Motor comes with good-quality gear. The gearbox is sealed and lubricated with lithium grease and requires no maintenance. Although the motor gives 1000 RPM at 12V, the motor runs smoothly from 4V to 12V and gives a wide range of RPM, and torque. The shaft has a hole for better coupling. Package Included: 1 x 12V 1000RPM Gear Motor Centre Shaft DC Geared Motor Heavy Duty Motor for Robotics
Out of stockDC 12V 100RPM Gear Motor Centre Shaft DC Geared Motor Heavy Duty Motor
[Gear Motor, Motor and Driver] Description: This 12V 100RPM Gear Motor can be used for heavy-duty applications, robotics, or any industrial or educational applications. It has a wide range of features for obtaining the optimal performance characteristics. 12V 100RPM Gear Motor is very easy to use and does not need expensive motor control circuitry. The 12V 100RPM Gear Motor are very popularly used in robotics applications. The gearbox of the motor helps in providing greater torque that is required to drive robotic vehicles. Based on the gearbox design the RPM and Torque of the motor will vary. Specifications: Working Voltage: 12V DC Rated RPM: 100RPM Load Current Max: 300mA No-Load Current: 60mA Torque Range: 5kg-cm (Approx) Stall torque: 28kg-cm (Approx) Features: 12V 100RPM Gear Motor comes with good-quality gear. The gearbox is sealed and lubricated with lithium grease and requires no maintenance. Although the motor gives 100 RPM at 12V, the motor runs smoothly from 4V to 12V and gives a wide range of RPM, and torque. The shaft has a hole for better coupling. Package Included: 1 x 12V 100RPM Gear Motor Centre Shaft DC Geared Motor Heavy Duty Motor
DC 12V 200RPM Gear Motor Centre Shaft DC Geared Motor Heavy Duty Motor for Robotics
[Gear Motor] Description: This 12V 200RPM Gear Motor can be used for heavy-duty applications, robotics, or any industrial or educational applications. It has a wide range of features for obtaining the optimal performance characteristics. 12V 200RPM Gear Motor is very easy to use and does not need expensive motor control circuitry. The 12V 200RPM Gear Motor are very popularly used in robotics applications. The gearbox of the motor helps in providing greater torque that is required to drive robotic vehicles. Based on the gearbox design the RPM and Torque of the motor will vary. Specifications: Working Voltage: 12V DC Rated RPM: 200RPM Load Current Max: 300mA No-Load Current: 60mA Torque Range: 5kg-cm (Approx) Stall torque: 28kg-cm (Approx) Features: 12V 200RPM Gear Motor comes with good-quality gear. The gearbox is sealed and lubricated with lithium grease and requires no maintenance. Although the motor gives 200 RPM at 12V, the motor runs smoothly from 4V to 12V and gives a wide range of RPM, and torque. The shaft has a hole for better coupling. Package Included: 1 x 12V 200RPM Gear Motor Centre Shaft DC Geared Motor Heavy Duty Motor for Robotics
DC 12V 500RPM Gear Motor Centre Shaft DC Geared Motor Heavy Duty Motor for Robotics
[Gear Motor] Description: This 12V 500RPM Gear Motor can be used for heavy-duty applications, robotics, or any industrial or educational applications. It has a wide range of features for obtaining the optimal performance characteristics. 12V 500RPM Gear Motor is very easy to use and does not need expensive motor control circuitry. The 12V 500RPM Gear Motor are very popularly used in robotics applications. The gearbox of the motor helps in providing greater torque that is required to drive robotic vehicles. Based on the gearbox design the RPM and Torque of the motor will vary. Specifications: Working Voltage: 12V DC Rated RPM: 500RPM Load Current Max: 300mA No-Load Current: 60mA Torque Range: 5kg-cm (Approx) Stall torque: 28kg-cm (Approx) Features: 12V 500RPM Gear Motor comes with good-quality gear. The gearbox is sealed and lubricated with lithium grease and requires no maintenance. Although the motor gives 500 RPM at 12V, the motor runs smoothly from 4V to 12V and gives a wide range of RPM, and torque. The shaft has a hole for better coupling. Package Included: 1 x 12V 500RPM Gear Motor Centre Shaft DC Geared Motor Heavy Duty Motor for Robotics
Keltron 2200uF 25V Radial Electrolytic Capacitor High Performance Capacitor
[Through Hole Capacitor] The 2200uF 25V Electrolytic Capacitor is a high-capacitance aluminum electrolytic capacitor designed for energy storage, voltage filtering, and decoupling applications. It is widely used in power supplies, audio amplifiers, industrial electronics, and electronic repair projects. In addition, the capacitor provides excellent ripple current handling and stable electrical performance. As a result, it effectively reduces voltage fluctuations, suppresses electrical noise, and improves overall circuit reliability. Because of its 2200uF capacitance, this capacitor can store a significant amount of electrical energy for smoothing DC outputs and reducing transient voltage spikes. Furthermore, the 25V rated voltage makes it suitable for a wide range of low-voltage power supply applications. The radial lead design allows easy PCB mounting and convenient installation. Moreover, the capacitor is manufactured using high-quality aluminum electrolytic technology to ensure long service life and dependable operation. This capacitor is commonly used in SMPS power supplies, audio amplifiers, inverter circuits, battery chargers, LED drivers, Arduino projects, and general electronic circuits. 🔹 Key Features High capacitance 2200uF value Rated voltage of 25V DC Radial lead electrolytic capacitor Excellent filtering and decoupling performance Low impedance design High ripple current capability Reliable long operational life Suitable for power supply and audio applications Easy PCB mounting 🔹 Technical Specifications Product Type: Aluminum Electrolytic Capacitor Capacitance: 2200uF Rated Voltage: 25V DC Tolerance: ±20% Mounting Type: Through-Hole (Radial Lead) Capacitor Type: Polarized Electrolytic Operating Temperature: -40°C to +105°C (varies by manufacturer series) Lead Spacing: Typically 7.5mm – 10mm (varies by batch) Application: Filtering, Decoupling, Energy Storage Series Resistance: Low ESR (depends on series) 🔹 Applications This capacitor is suitable for: Audio amplifier circuits Power supply filtering SMPS circuits Voltage stabilization circuits Battery chargers Inverter systems LED driver circuits DIY electronics projects Industrial electronic equipment Electronic repair work 🔹 Package Includes 1 × 2200uF 25V Radial Electrolytic Capacitor
1uf / 63v Electrolytic Capacitor
[Through Hole Capacitor] Electrolytic decoupling capacitors 1uF / 63V. These capacitors are great transient/surge suppressors and work well in high-voltage and audio applications. High-quality radial electrolytic capacitors. Specifications: Value: 1uF Rated Voltage: 63V Package Content: 1x capacitor
10uf / 63v Electrolytic Capacitor-Keltron
[Through Hole Capacitor] Electrolytic decoupling capacitors 10uF / 63V. These capacitors are great transient/surge suppressors and work well in high-voltage and audio applications. High-quality radial electrolytic capacitors. Specifications: Value: 10uF Rated Voltage: 63V Package Content: 1x capacitor
100uf / 25v Electrolytic Capacitor Keltron
[Through Hole Capacitor] Electrolytic decoupling capacitors 100uF / 25V. These capacitors are great transient/surge suppressors and work well in high-voltage and audio applications. High-quality radial electrolytic capacitors. Specifications: Value: 100uF Rated Voltage: 25V Package Content: 1x capacitor
Out of stockL293D Stepper Motor Driver IC Chip
[Semiconductor ICs] L293D Stepper Motor Driver IC is a dual H-bridge motor driver integrated circuit (IC). Motor drivers act as current amplifiers since they take a low-current control signal and provide a higher-current signal. This higher current signal is used to drive the motors. Features: Featuring Unit rode L293 and L293D Wide Supply-Voltage Range: 4.5 V to 36 V Separate Input-Logic Supply Internal ESD Protection Thermal Shutdown High-Noise-Immunity Inputs Output Current 1 A Per Channel (600 mA for L293D) Peak Output Current 2 A Per Channel (1.2 A for L293D) Output Clamp Diodes for Inductive Transient Suppression (L293D) Applications: High Current Motor Driver IC. Dual H-bridge for controlling up to two motors at a time. Ideal for Inductive load decoupling from the main/control unit. A wide voltage range allows for an adaptive voltage range control. Package Includes: 1 x L293D Driver IC
Out of stock12V 6 Channel with Light Coupling Relay Module
[Relay Module] This 6 Road/Channel Relay Module (with light coupling) 12V module meets the safety standard as control areas and load area have the isolation groove. Optical coupling isolation module. The triggering of the 6 Road/Channel Relay Module is reliable, more stable. The double FR–4 circuit board design, high-end SMT process. It has power and relay operation instructions. Relays terminals (C, NC, NO) are accessible through screw terminals which makes wiring up the board very easy. The inputs of the 8 Channel 12V Relay Module are isolated to protect any delicate control circuitry. A wide range of microcontrollers such as Arduino, AVR, PIC, ARM and so on can control it. The use of such high-voltage relay eliminates the risk of heating up of the relay as electromechanical relay limit the current consumption in accordance with a voltage rating. Module interface: The positive (according to the relay voltage VCC: connect power supply) GND: connect power negative IN1: relay module (effective) high-level trigger signal trigger end IN2: relay module (effective) high-level trigger signal trigger end IN3: relay module (effective) high-level trigger signal trigger end IN4: relay module (effective) high-level trigger signal trigger end IN5: relay module (effective) high-level trigger signal trigger end IN6: relay module (effective) high-level trigger signal trigger end IN7: relay module (effective) high-level trigger signal trigger end IN8: relay module (effective) high-level trigger signal trigger end Meaning of High level and Low-level High-level trigger refers to using the anode voltage at the VCC connection way of a trigger and triggers the end when the trigger side has a positive voltage or to trigger voltage when the relay is off. Low-level trigger refers to using the negative voltage at the GND connection way of a trigger and triggers the end when the trigger side has 0 v low voltage or voltage to can trigger, the relay is off. Features : Equipped with high-current relay 10A@250VAC / 10A@30VDC It can control both AC and DC appliances such as Solenoids, Motors, lights, fans, etc High-quality screw terminals (Terminal Block) provided (C, NC, NO) for quick and easy connection A freewheeling diode to protect your microcontroller Input Signal Pin connected to Burg stick for easy accessibility LED status indicators to indicate the relay ON/OFF status Mounting holes provided Signal input with a high-level signal, the common and often start conduction; The relay can directly control all kinds of equipment and load; One often opened a normally closed contact; Blue KF301 terminal line more convenient. It is also able to control various appliances and other types of equipment with a large current. Red working status indicator lights are conducive to safe use. Widely used for all MCU control, industrial sector, PLC control, smart home control. Package Includes: 1 x 12V 6 Channel with Light Coupling Relay Module
Out of stock5V 6 Channel Low Level Relay Module with Light Coupling
[Relay Module] It is a 5V 6 Channel Low-Level Relay Module with Light Coupling. The relay normally open interface maximum load: AC 250V/10A, DC 30V/10A. With optocoupler isolation, strong drive capability, stable performance; trigger current 5mA, module working voltage: DC 5V. Each channel of the module can be triggered by a jumper to set a high level or a low level. Fault-tolerant design, even if the control line is disconnected, the relay will not move. With status indicator: power (green), 6-channel relay status indicator (red). All module size interfaces can be directly connected through the terminal block, which is convenient and practical. Features: 6-way relay output module contact capacity is 10A 250V. input IN1, IN2, IN3, IN4, IN5, IN6 signal, a low level is effective. Using single-chip design, reliable performance, strong anti-interference, no false triggering, superior performance. The trigger terminal has optocoupler isolation, the independent external power supply can trigger completely isolated. Each relay has an activity indicator light. With 4 fixed bolt holes, easy installation. Support all SCM control. It is applicable to the industrial sector, PLC control and home intelligent control. Package Includes: 1 x 5V 6 Channel Low-Level Relay Module with Light Coupling.