THIS IS FOR THE PURCHASE OF BULBS THAT HAVE 13 LED’s - IN A SINGLE OR MULTI PACK. THIS IS THE MOST VERSATILE BULB AVAILABLE, FUNCTIONING IN TAIL LIGHTS IN VEHICLES AND TRAILERS IN EITHER 12V OR 24V SYSTEMS IN TRUCKS OR TRAILERS. CLEAR AND BRIGHT. ALSO SAVES A LOT OF MONEY PER BULB BY BUYING A MULTI-PACK.