Audio Input Signal Selector Relay Board/Signal Switching Amplifier Board + RCA L

Audio Input Signal Selector Relay Board/Signal Switching Amplifier Board + RCA

MICRO USB 5V 2/4/8 Channel USB Control Relay Module 1 Channel 5-30V Delay Relay

Latching relay board 12vdc ( single pushbutton input to latch / unlatch relay )

Optocoupler / Photocoupling Isolation Board 6N137 5V NPN Input 3.3V~24V DC

7-24V Modbus Rtu 1/2/4 Channel Relay Module Switch input output RS485/TTL UART

XH-M138 high current switch relay board 12V input switch control 30A output