The kit I just bought from EIS is a BMW factory kit with all the necessary parts to enable bluetooth and voice recognition. The boxes had BMW markings and factory part nos. on them, and is a Visteon type unit. The instructions are written for a BMW tech to install, but are easy enough for anyone to DIY (It took me about an hour). Basically, you get a factory kit for a discounted price. My kit cost a little under $700 which included the bluetooth module w/voice recog., eject box w/pairing button, and snap in adapater to hold my Motrola E815. Note that this price included a snap in adapter which you may or may not need or want, so you can delete it for even lower cost. I didn't need an antenna because you can just use your existing BMW Assist antenna (I had to remove the BMW Assist module in my '04). EIS was really great with any questions I had too, and made sure I got all the right parts the first time. Talk to Randy at EIS, he was very helpful.