Kuryakyn 919 Super Bright Pulsing Bulb Self-modulating bulb warns drivers behind you of your deceleration Apply the brakes and the bulb pulses rapidly and then remains brightly illuminated as long as the brakes are applied Includes spare G4 2-pin Halogen bulb Replaces 1157 bulbs in run-brake taillight applications Replaces 1157 bulbs in run-brake taillight applications