A2513200158 Air Pump Valve Control Unit Compatible for Mercedes-Benz R-Class W251 2006-2013[description]Description The air suspension system is a stabilization system that regulates the car body, mainly composed of air compressors, accumulators, control units, sensors, and control valves. According to the different road conditions and the signal from the distance sensor, the trip computer will determine the height of the vehicle, and then control the air compressor and exhaust valve to automatically compress or extend the spring, thereby