BMW E39 owners who wish to transition from their original halogen bulbs to HIDs often face a challenge due to the unique design of the housing clip. Fortunately, these specialized adapters have been crafted to solve this issue, making the HID bulb fit seamlessly. Before purchasing, it's advised for owners to inspect their headlights for a particular plastic socket located behind the bulb to ascertain if these adapters are essential. Notably, all E39 housings are tailored for H7 bulbs. The innovative slotted design of the adapters facilitates the easy insertion of the bulb's wiring from the side. Once installed, the bulb is firmly anchored in place by the original clip assembly, mirroring the stability of the original setup.