Evan Designs U5TR Bright Slow Red Tower Light LED 5mm slow blinking red LED with 18" overall wire length, great for towers 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