H4 bi-xenon HID kit includes 2x 75W HID bulbs, 2x 75W FAST START ballasts. H4 bi-xenon uses the same xenon bulb for low beam and high beam. A relay is necessary for the bulb to work in daytime running mode and high beams. The relay is included in the kit.
Ballast size: 3" wide x 4" long x 1" high