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 Autel, Bosch, iCarsoft, etc.) to remove old error codes from a faulty seat mat stored in the airbag control unit. Once connected, your diagnostic tool can clear the error codes and turn off the SRS/airbag warning light. Please note that errors related to safety systems do not clear automatically. Before purchase, scan your vehicle with a diagnostic tool to confirm the SRS/airbag warning is caused by a defective seat mat. Name: Car Seat Occupancy Mat Sensor SRS Bypass Emulator Fitment Type: Direct Replacement Condition: Fitment: For Mercedes-Benz A-Class W176 (2012-2018) For Mercedes-Benz B-Class W246 (2011-2018) Color: As Shown Material: Plastic Package Contents: 1 x Car Seat Occupancy Bypass MAT SRS Emulator Sensor Note: Light reflection and different display settings may cause slight color variations between the product image and the actual item. Measurement may vary by +/- 1-3 cm.