Already have an MLED or D2S projector on hand and only need the adapter? Then this is what you're looking for. The kits include the adapters and hardware needed to complete the retrofit with your components.
Please note that these are only tested and confirmed to fit with the MLED 2.0 projector, Morimoto Micro D2S projector, and Lightwerkz Micro D2S projector. I cannot confirm fitment of any other brands and I will not speculate on it either. So please do not ask.
Fitment has not been confirmed on the E34 Bosch Smilies.
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.