Module parameters:1. Size: 50.5mm (length) * 38.5mm (width) * 18.5 (height)2. Weight: 31g3.PCB color: black4. There are 4 fixing screw holes around the board, the hole diameter is 3.1mm, which is convenient for installation and fixing.5. Use high quality relays, single pole and double throw. a common end, a normally open end, and a normally closed end6. Optocoupler isolation, good anti-interference7. Low level pull-in, high level release. The status indicator is on when the inverter is closed, and the status indicator is off when released.8. VCC is the system power supply, and JD_VCC is the relay power supply. Plug in the jumper capElectrical parameters:Supply voltage: 3.3VCurrent: greater than 100mALoad: 250V 10A AC or 30V 10A DCWiring instructions:VCC: system power supply positiveGND: system power supply negativeIN1--IN2: Relay Control Port(Do not reverse, causing the module to burn out and we will not return it.)