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 or 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 or warning is caused by a defective seat mat. for C-Class W203 Saloon or 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 or C209 Coupe (2002-2004) before facelift for CLK W209 or A209 Cabriolet (2002-2004) before facelift Material:Plastic and Metal colour:As shown Package Contents: 1 x 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. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.