This is my Kato Southern Pacific f7 locomotive. This was the first quality locomotive I got. It has a flywheel drive and can pull more cars then any of the other loco's I have including the E8. The signal to the right of the locomotive has 2 very small LEDs in it. The ladder on the back of the signal is made from the wires that power the LEDs. The signal is changed from red to green by reversing the polarity.