The dwarf signals are prototypical HO scale with a black plastic body and silver hood.
Each dwarf signal comes with one L.E.D. 3mm Bi Polar 2 color (red/green) wired with a 470 ohm limiting resistor.
A 3 volt power sorce is recommended.
If you are using Tortoise(tm) switch machines you only need to drill a ¼ hole in the location desired and hook the purple wire to # 1 terminal and the yellow to the # 8 on the Tortoise.If you fine the dwarf signal is lite incorrectly you just need to reverse the wires.