Model #5410 is a complete kit with crossing detector and activation switches. The detector operates with trains traveling in either direction at any speed, using the small momentary activation switches that are imbedded in the track. The timing of the signal shutoff after the train passes is adjustable. The detector requires 12V DC power; two "D" batteries (sold separately) will provide 30+ hours of power to the signal drive.
Model #5400 does not include the detector but can be used with a Circuitron or other unit supplying 12V 15MA of current.
Detectors with Switches (#147-5420) are available separately to power signal lights, crossing gates and similar items; Track Switches (147-5430, pkg(4) are also available separately to operate sounds and other accessories. These items are suitable for use with HO and larger scales.