These are NEW LONG LED bulbs for the 1157 type taillight and work with taillight that has extra room in the taillight for a longer light. Typically a tailllight lens on a snowmobile, trailer, or motorcycle will have enough room. If the bulb mounts sideways, there is enough room. This unit is 8mm longer than the stock 1157 bulb, or about 5/16" taller. 20 LEDs are carefully mounted all around the base and top of the bulb to make it the most luminant LED bulb ever made. Rated life is 10,000 hours and draws virtually no electricity (about 15 milli-amps). Sold per each light.