This is a brand new set of two BMW E39-1 (5 Series 1997 - 2000) HID Adaptors. If you have bought HID Xenon conversion kit for your BMW E39 then you will need this HID bulb holder. They enable you to use H7 HID kit on your H7 halogen headlight housings without modification, by holding the H7 HID bulb in its place to provide correct lighitng output and beam pattern. Installing a H7 HID kit without these adaptors, would not be possible. Please note that these Adaptors only work with aftermarket H7 HID Conversion kits on BMW E39 5 Series 1997 - 2000.