The kit consists of a ballast, (power supply unit 1”x5x3” overall or 1x4x3 not including the integral mount tabs) wire harness with plug, HID bulb(s) in PAR 36 or Par 46, (standard 4.5” or 6”) bulb sizes and even other custom configurations as needed. Mounting hardware can also be included as needed, and is very simple and minimal. (Three screws and nuts, or nut-plates or riv-nuts, 2 butt splices, and a ring terminal generally). Installation is quick and simple with the three fasteners for the ballast. The bulb/reflector assembly just mounts in place of the old bulb with no changes necessary.