The 153IR sends a signal across your tracks. When the signal is reflected, the accessory to which the 153IR is connected begins to operate. Controls for time delay (from zero to five seconds) and signal sensitivity give the 153IR tremendous flexibility in controlling the exact moment you want your accessory to operate.

Die-cast metal structure
Infrared sensors detect passing trains and activate connected accessories
Time delay adjustment knob (From 0 to 5 seconds)
Dimensions: 5" x 4 1/2" x 3 1/2"