Module parameters:
1. Size: 75mm (length) * 55mm (width) * 18mm (height)
2. Weight: 61g
3. PCB color: blue
4. With four fixed screw holes around， hole diameter 3.1mm， easy installation and fixation
5. Relay uses high quality Songle relay， SPDT. One common terminal， one normally open， and one normally closed
6. Optocoupler isolation， good anti-jamming performance
7. Low level close， high level release. Status indicator lights up when closed and turns off when released
8. VCC for the system power， JD_VCC relay power. Default shipped as 5V relay， just plug in jumper
9. Relay maximum output: DC 30V / 10A， AC 250V / 10A

Wiring instructions:
VCC: positive pole of system power supply
GND: negative pole of system power supply
IN1 - IN4: relay control port

1 x Relay Module