This self-modulating bulb warns drivers behind you of your deceleration. Apply the brakes and bulb pulses rapidly and then remains brightly illuminated as long as the brakes are applied. Sold as a pair to outfit the Tour-Pak® H-D® Ultra Classics or individually to cover most 1157 taillight applications. Includes a spare G4 2-pin Halogen bulb.Fits: Replaces 1157 bulbs in run-brake taillight applications
