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 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. These warnings can be turned on by at least 6 sensors mounted in the seat. The emulator solves the problem caused by a faulty seat mat only. The emulator not solve your problem if a different sensor is faulty - the SRS/ warning light still be present after connecting the emulator and removing the error present in the diagnostic tool. Name:Car Seat Occupancy Mat Sensor SRS Bypass Emulator Fitment Type:Direct Replacement Install Fitment: for E-Class W211 Saloon/Sedan (production years: 2004-2009) for E-Class S211 Estate (production years: 2004-2010) for C219 (production years: 2004-2010) for S-Class W221 (production years: 2005-2013) for /S-Class Coupe C216 (production years: 2006-2014) Color:As Shown Material:Plastic Package Contents: 1 x Car Seat Occupancy Bypass SRS Emulator MAT 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.