GL1800 01-17 Red Ultra Flash LED Bulbs. Designed to increase visibility. PATHFINDERLED bulbs are known to be one of the brightest with "instant intensity" and now have an ultra-flash feature.This new ultra-flash feature is programmed into the bulb to alert other drivers you are braking. The bulbs will emit a series of 4 quick flashes, and then stay solid until the next time your brakes are applied. Sold as pair