2 light signal red/green signal offset platform starter LH/RH round head This short post signal is used mainly on station platforms. A red light is used to indicate stop and the green light indicating permission to proceed or route clear. An offset signal is placed in areas where driver visibility of the signal could be impaired if a standard signal were used. This signal is ready to use out of the box and features a pre-wired resistor to allow the safe operation of the signal from a 12 Volt DC power supply.