2 light signal redgreen T junction square head This redgreen T junction signal is mainly used at diverging routes 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 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