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 Autel, for Bosch, for iCarsoft etc.) to remove old errors of a broken seat mat that are stored in the airbag control unit. Once you connect the emulator your diagnostic tool will be able to remove old errors and turn off the SRS/airbag 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/airbag warning is caused by a defective seat mat. Name:Car Seat Occupancy Mat Sensor SRS Bypass Emulator Fitment Type: Direct Replacement Install Condition: Type: 3+2Pin 2 Heads Fitment:for Mercedes Benz C-Class W203 Saloon/Sedan (2000-2004) before facelift Colour: 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.