These Dwarf Signals are very close to scale size providing realism on your layout. We carry primarily O Scale signals that work with our products or may be used as standalone. The Dwarf signals work directly with our controllers or require an anode common supply with the appropriate dropping resistor to limit the current to the red and green LEDs.
Anode common you ask? That means both of the positive connection leads from the LEDs are internally tied together. Most of the time you can connect the common anode to a 5 VDC regualted supply and put the appropriate sized resistor in the negative lead to ground. Our controller provides the supply and resistors along with an electronic switch to turn on the red or green LED depending on a trigger input.
The Red over Green option may take a month or two to order and the minimum accepted order is 10 of this configuration.