These are NEW LED bulbs for the 1156 type (round metal base) - single function light (like turn signal) and work with ANY mounting position in the taillight. 15 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). Used most commonly in interior light sockets, RVs, Boats, trailers etc. Use white LED when taillight has window to light license plate also. Sold per each light.