The seat occupancy mat is a sensor mounted in the front passenger seat. The emulator simulates a situation of a person sitting in the passenger seat with a seat belt fastened. To make the emulator work you need a diagnostic tool (like for , , etc.) to remove old errors of a broken seat mat that are stored in the control unit. Once you connect the emulator your diagnostic tool will be to remove old errors and turn off the SRS/ warning. Unfortunately, the errors related to the safety systems are not removing automatically. Before purchase, please scan your car with a diagnostic tool to make sure your SRS/ warning is caused by a defective seat mat. for C-Class W203 Saloon/Sedan (2000-2004) before facelift for C-Class S203 Estate (2000-2003) before facelift for C-Class CL203 Sport Coupe (2000-2008) for CL203 (2008-2011) for CLK W209/C209 Coupe (2002-2004) before facelift for CLK W209/A209 Cabriolet (2002-2004) before facelift Material:Plastic + Metal colour:As shown Package Contents: 1 * Bypass emulator Only the above package content, other products are not included. Note: Light 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.