HID kits come with the light, wire harness, and ballast boxes. the bulbs that you find at autozone and stores of the like arents true HID's, just "zenon" bulbs or whatever they wanna be called. real HID's come in the kits. check out the sponsors here on the forums, there are quite a few that sell a lot of quality HID kits, and installation is easy. also, dont forget to get a relay for the HID's if you do decide to buy them.