The power supply method of the module: take power from the car insurance, this product does not need to be connected to the ACC power supply, just connect the battery power supply and the ground wire Module installation location: 6-disc CD of the co-pilot of the vehicle Brief introduction to the module installation process: The optical fiber conversion cable provided with the product is plugged in with the 6-disc CD optical fiber interface of the car, connected to the power supply of the product, and connected to the ground wire. Product name:for Audio Optical Decoder Fitment: For A8/A8L 2004-2009 2GMMI systems For A6/A6L 2005-2009 2GMMI system For 2005-2009 2GMMI system Note:This product is only suitable for 2G MMI system, the product only has one audio input function, no video input function Built-in Bluetooth module 5.0 Module access voltage:12V Colour:Black Material:Metal+ABS Package Contents: 1 * Audio Fiber Decoder Box 1 * audio cable 1 * power cable Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.