Compatible Fiber-Optic Interface:When installing this interface into your Ffor Mercedes-Benz, you must make sure that the Fiber-Optic signal loop is not broken. If you have other devices which can include original CD Changer, satellite radio, and telephone module, they must stay connected so the fiber optic signal loop is consistent.To identify if you have a Fiber-Optic MOST factory-amplified audio system, you can check the vehicle in the following ways:Some vehicles will have clear markings on the speaker grills indicating the presence of an upgraded audio system.You can also check with the original order notes/invoice from when the car was purchased from the factory, the upgraded sound system with an amplifier would show on the options list.Compatible Car Models:for Mercedes-Benz:1.S/CL class 2000-20032.E class 2000-20023.SL 2003-20044. C/CLK 2001-20045.ML 2000-2005Material:ABScolour:BluePackage Contents:1 x Fiber-Optic(MOST) Decoder Box1 x Connection CableOnly the above package content, other products are not included.Note: Light shooting 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.