The 762 P/N is the upgraded BMW microphone, that has only recently become available from BMW. It has better noise cancellation than the 5 year old, and less expensive 84 31 8 380 319 Microphone.
The 319 mic is easily distinguished from the 762 microphone. The 319 mic has a GREEN base as shown in the below LEFT picture and the 762 as shown below in all Black on the RIGHT. The 319 mics are still floating around from other vendors as they are much cheaper. Just as we recommend the newer ULF modules due to their higher performance and better sound quality we also recommend the better 762 microphones when you install BMW's Bluetooth kits
BMW Microphone installation Video