These are the adapters necessary to retrofit the Morimoto or Lightwerkz Micro D2S projector into your e30 or e34 projector style headlights. These work with the four types of projector style headlight: US Ellipsoid, Hella Smiley, Bosch Smiley, and the Depo Smiley. All the hardware necessary to retrofit your projector is included.
If you know your way around a car, these will likely be very straightforward to install. But please do your due diligence before purchasing. Understand what a sealed beam headlight is, what it takes to swap to a projector assembly, etc. I'm happy to answer questions, but please take a few minutes to browse some forum posts or read through the tutorials.
All HID components and relay harnesses use the 9005/9006 style connectors found on cars equipped with US Ellipsoids. If your car does not have these style connectors on it, you will need to modify your car's connectors or make adapters.