2 light signal redgreen standard leftright offset square head This full length signal is placed at the side of the track It is suitable for any layout based from around 1970 when this style of signal head came into use & examples could still be found on the network until 2009 when the new slimmer signals became standard although this replacement programme began around 2000 A red light is used to indicate stop & 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 & features a prewired resistor to allow the safe operation of the signal from a 12 Volt DC power supply