Lifetime LED's H4 Bulb is the next generation H4 headlight bulb. The H4 Bulb is brighter and more controlled than the previous model. The H4 Headlight bulb is used wherever you use the 9003 bulb. Lifetime LED Lights H4 Bulbs carry Lifetime LED's Lifetime warranty and won't leave you in the dark. The use of Cree LEDs produce a headlight bulb with 3200 lumens on low beam and 3600 lumens on high beam (each bulb). This makes the H4 / 9300 brighter than most HID headlights on the market. You don't need to run a harness to power these (like you have to with HID). The error cancelling harness is included in your package for all Canbus systems.