Features 1、EQUIPPED WITH CHIP AND CONTROLLER: 4 channel Micro USB relay module has stable USB to serial port chip and microcontroller 2、SWITCH CONTROL: Serial commands can be sent on the computer using serial debugging software to control the opening and closing of the 4 channel relay 3、EASY TO USE: Onboard for HID control chip, drive free, plug and play, convenient for you to use, useful and practical 4、PROTECTION FUNCTION: The module has overcurrent protection and relay diode freewheeling protection, very safe 5、LONG SERVICE LIFE: Onboard 5V, 10A 250VAC, 10A 30VDC relay, the service life of the relay can be continuously pulled in 100,000 times Specification Item Type: 4 Channel Relay Module Material: PCB copper plate Package List 1 x 4 Channel Relay Module