Evan Designs U56 5 mm Bright Orange LED, Pkg=5 5mm orange LED, We have added a resistor, rectifier, and capacitor, comes assemled The electrical componets allow you to use AC/DC/DCC, 7-19volts, completely assembled You can use a 9v battery, track power, 12v adapter to light our LEDs each set comes with a resistor, capacitor & rectifier, thus no polarity issues A 12 volt 2 amp adapter (PDC12) will run 100 LEDs