This is a DCC Concepts DCD-SDC6 DCC Decoder Converter 3 Wire To 2 Wire (6 Pack)

Pack of six solenoid decoders. The SDC is a clever wee device that takes the outputs from a 3-wire accessory decoder and turns them into a 2-wire reversing DC decoder, allowing you to use most solenoid accessory decoders to power Kato, Cobalt or other brands of point motor. Please note that for motor drive decoders you will also need to set ‘power on’ time for between 2 and 4 seconds.