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 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 used to remove old errors and turn off the SRS warning. Unfortunately, the errors related to the safety systems are not removed 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 A-Class W176 (2012-2018) For B-Class W246 (2011-2018) Colour: As Shown 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 to be slightly different from the real thing. The measurement allowed error is +/- 1-3cm.