Feature:1. PC Control: Comes with a stable USB to serial port chip and microcontroller. It can use serial debugging software to send serial commands on the computer to control the opening and closing of the 2 channel relay.2. HID Chip: With HID control chip on the board, the relay module is driver free, plug and play. Very convenient!3. Long Life Span: On board 5V, 10A, 250VAC relay, the service life of the relay can be continuously pulled in 100,000 times.4. Protective Function: Our relay module has functions for overcurrent protection and relay diode freewheeling protection.5. PCB Board: Made of PCB board, our relay module has low power consumption, and a long life span.Specification:Item Type: Relay ModuleMaterial: PCB Copper Plate.Package List:2 x Relay Module Note:You must insert the device first and then open the software, because only when you open the software will the software detect whether there is a device inserted and establish an automatic connection.