2 Channel Relay shield for Arduino UNO can be used in several applications like remote control, on/off AC or Dc load and any circuits which required isolated high current and high voltage. Relay 1 connected to Digital pin D2 and Relay 2 can be controlled through D12 of Arduino PIN. Both relay has optocoupler in input for isolation which protect Arduino from any EMI noise and complete isolation between high volt/current at relay outputs. Relay shield required separate 12V DC. Two LED indicate the Relay operations. J1,J2 provided In case single supply for relay and Arduino required.