Specification: 1. Dimensions: 50.5mm * 38.5mm * 18.5mm 2. Weight: 31g 3. PCB color: black 4. board around with four fixed screw holes, hole diameter 3.1mm, easy to install and fixed 5. Relay selection of high-quality loose relay, single-pole double-throw. A common end, a normally open end, a normally closed end 6. Optocoupler isolation, good anti-interference 7. Low level pull-in, high-level release. Pull the status indicator light, release the status indicator is off 8. VCC for the system power, JDVCC for the relay power. Plug in the jumper cap Electrical parameters: Supply voltage: 5VDC Current: Larger than 100mA Load: 250V 10A or 30V 10A DC Wiring instructions: VCC: The system power is positive GND: Negative pole of the system power supply IN1 - IN2: Relay control port