A 3mm red and warm white LED. Both in the same bulb. These are already set up with a resistor to work on your DC Model Train Power Supply 7-19 volt DC only.
These bidirectional bipolar LEDs will be red in reverse and warm white in forward. Choose this 2-lead bi-directional LED when you need your DC train or trolley to have red lights in reverse. Also great for other railroad track side effects.