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 , for , 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. Name:Car Seat Occupancy Mat Sensor SRS Bypass Emulator Fitment Type:Direct Replacement Install Fitment: For CLK W209 2006-2009 For MB CLK W209 2006-2009 C W203 2005-2007 Note: Installation guide not included, we strongly recommend you professional installation. Please check as much as possible to make sure the item is what you need. The Compatibility Is Just For Please Compare The Part Number With Your One Before Purchasing! Colour:Photo Color Material:plastic Package Contents: 1 x Car Seat Bypass Emulator Sensor 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.