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 the airbag control unit caused by a faulty seat mat. Once connected, the emulator allows your diagnostic tool to clear stored errors and turn off the SRS/airbag warning light. Please note that these safety system errors do not clear automatically. Before purchasing, scan your vehicle with a diagnostic tool to confirm that the SRS/airbag warning is due to a defective seat occupancy mat. Name: Car Seat Occupancy Mat Sensor SRS Bypass Emulator Fitment Type: Direct Replacement Condition: Fitment: For Mercedes-Benz A-Class W176 (20122018) For Mercedes-Benz B-Class W246 (20112018) 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 variations in color between the image and the actual item. Measurement may vary by 13 cm.