The Relay Shield utilizes four high quality relays and provides NO/NC interfaces that control the load of high current. Which means it could be a nice solution for controlling devices that couldn’t be directly controlled by IIC bus. Standardized shield form factor enables smoothly connection with the Raspberry Pi . The shield also has four dynamic indicators show the on/off state of each relay. Features:Raspberry Pi compatibleInterface:IIC , Three hardware SW1 (1, 2, 3) select the fixed I2C-bus addressRelay screw terminalsStandardized shield shape and designLED working status indicators for each relayCOM, NO (Normally Open), and NC (Normally Closed) relay pins for each relayHigh quality relaysWorking status indicators for each relay