The occupancy mat is a sensor mounted in the front passenger . The emulator simulates a situation of a person sitting in the passenger with a belt fastened. To make the emulator work you need a diagnostic tool (like for , , etc.) to old errors of a broken mat that are stored in the control unit. Once you connect the emulator your diagnostic tool will be to old errors and turn off the / warning. Unfortunately, the errors related to the systems are not removing automatically. Before purchase, please scan your car with a diagnostic tool to make your / warning is caused by a defective mat. Name: Car Occupancy Mat Sensor Bypass Emulator Fitment Type: Direct Replacement Install 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 colour: As shown Package Contents: 1 x Car Bypass Emulator 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.