1Professional manufacturing, this is perfect to fit for MMI AMI 3G / Q5 / A4L / A6L / Q7 / A5 / S5. 2The 4pin and 12pin connectors plug into the back of the CD host connector. More stable connection, remarkable performance, easy to plug and play installation. 3Unconventional Bluetooth function can support DSD large-capacity transmission. You can hear music from your phone/tablet/mp3 (they should have Bluetooth capabilities). 4Bluetooth version 5.0, compatible with other versions of Bluetooth 2.0, 3.0, 4.0, 5.0, can support commonly used MP3 format audio, and also support WMA, WAV, FLAC and other highquality audio format decoding. 5Match your mobile phone or tablet to the Bluetooth module, then select AUX from the radio, and then you can use your mobile phone to play music through the car speakers.