This is an 8-channel relay board that runs on 12 volts. Any microcontroller or other control system circuits can be used to control loads rated up to 250V 10A AC directly. 
Each relay has three connections: Common (C), Normally Open (NO), and Normally Closed (NC), all of which are connected to three-pin screw terminals, making it simple to connect and disconnect. To make debugging easier, the board incorporates a power indicator and a relay status LED. The board's header pins receive power input and relay control signals.

Specification