This is the most popular H4 headlight bulb, because it is the brightest one that works with your stock headlight wiring. Combined with a good pair pair of H4 headlight assemblies, such as the Bosch
ones we have on sale, these bulbs just plug right into your stock wiring. Installing relays (such as our HRK1 kit for 80-85 Vanagons) may improve performance but is not necessary. Notes: When installing an H4 bulb, you must not touch the bulb (only the base), as the oil from your fingers will cause the bulb to fail; therefore we do not warranty bulbs.