Features: UART serial port protocol, support two interfaces, USB_B female interface (CH340 serial chip), RS232 interface (TTL level). USB interface fit for Windows operating systems, fit for Linux operating systems. Open, close, jog, self-lock, interlock, delay, all open, all closed 8 working modes (8-byte command no delay mode). Two kinds of instructions: AT command and 8-byte command, the two commands are automatically recognized, no need to switch. Maximum delay of 9999 seconds under AT command. Specification: Power:DC 12V Working Current:Standby 12mA, 1 relay turns on 40mA, 2 relays turn on 67mA, 3 relays turn on 95mA, 4 relays turn on 121mA, 5 relays turn on 147mA, 6 relays turn on 173mA, 7 relays turn on 198mA, 8 relays turn on 223mA. Size:92 x 62 x 19mm / 3.62 x 2.44 x 0.75in Weight: 120g/4.23oz Maximum load: 10A/250VAC, 10A/125VAC, 10A / 30VDC, 10A / 28VDC, 10A / 12VDC Package List: 1 x Relay Module 1、UART serial port protocol, support two interfaces, USB_B female interface (CH340 serial chip), RS232 interface (TTL level). 2、USB interface fit for Windows operating systems, fit for Linux operating systems. 3、Open, close, jog, self-lock, interlock, delay, all open, all closed 8 working modes (8-byte command no delay mode). 4、Two kinds of instructions: AT command and 8-byte command, the two commands are automatically recognized, no need to switch. 5、Maximum delay of 9999 seconds under AT command.