PLEASE NOTE THESE SIGNALS ARE NOT SUITABLE FOR DCC LAYOUTS
The signal is operated by sensors when a locomotive passes over them. From green it turns to red and 3 seconds later turns to yellow. After a further 3 seconds it returns to green. To power these signals from a Kato controller you require an Automatic Signal power supply 24-844 up to 3 signals can be powered through this. This will then plug into an adapter 24-829 which in turn clips to the side of the controller.
This version has the signal on the right hand side of the track, as per North American practise.