Measuring devices - brand generique - DC 5V Module Relay Control Board Coupling With Optocoupler 50.5 X 38.5 X 18.5 mm .5 X 18.5 mm Description: 2 Channel 5V SPDT Relay Output Modules. With optocoupler. One common end, one normally open end and one normally closed end. Optocoupler isolation, good anti-interference. Low level extraction and high release. The status indicator is on when the pump is closed and the status indicator is off when you release it. There are 4 fixing screw holes around the board, the hole diameter is 3.1mm, which is convenient for installation and fixing. VCC is the system power and JD_VCC is the relay power. Specification: Supply Voltage: 5V DC Current: 100mA Load: 250V 10A AC / 30V 10A DC Size: 50.5 x 38.5 x 18.5mm / 1.99 x 1.51 x 0.73inch Instructions wiring diagram: VCC: system power supply positive GND: system power supply negative IN1 - IN2: Relay control port Package includes: 1 x 2-channel 5V relay module Note: The size above is measured by hand, please allow some variation. slight difference. THANKS !