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 (such as for MB, for Benz, etc.) to remove old errors from a faulty seat mat stored in the control unit. Once you connect the emulator, use your diagnostic tool to clear the old errors and turn off the SRS warning light. Errors related to safety systems are not cleared automatically. Before purchase, please scan your vehicle with a diagnostic tool to confirm that your SRS warning is caused by a defective seat mat. Name: Car Seat Occupancy Mat Sensor SRS Bypass Emulator Fitment Type: Direct Replacement Installation Compatible With: For CLK W209 2006-2009 For MB CLK W209 2006-2009 C W203 2005-2007 Note: Installation guide not included; professional installation is strongly recommended. Please verify compatibility to ensure the item meets your needs. Compatibility information is for reference only; please compare the part number with your original before purchasing. Color: As shown in photo Material: Plastic Package Contents: 1 x Car Seat Bypass Emulator Sensor Only the above package content is included; other items are not included. Note: Light reflection and different display settings may cause slight color variations between the image and the actual item. Measurement error allowed is +/- 1-3 cm.