Bilstein B4 OE Replacement (Air) Air Spring Fits select: 2007-2013 MERCEDES-BENZ S 550

B4 Series Front Driver or Passenger Side Non-Armored Monotube Complete Strut Assembly (44-109462) by Bilstein. Quantity: 1 per Pack. The Bilstein B4 air suspension module. The only fully functional module for all air suspension systems in uncompromising OE quality. High-quality air suspension modules in uncompromising original manufacturer quality have only been available for a few years. Unfortunately this is why in the meantime, spare parts of significantly poorer quality and often with considerably restricted functions have spread on the market. The delicate axial bellows of the air spring provide very sensitive spring behaviour with a comparably low rolling radius. This ensures optimum functionality even in confined working chambers. Due to the permanent load (contraction, extension, different pressures and temperatures), the material is worn out and may eventually leak. If the air bellows cannot be inflated any more, the vehicle is no longer fit to drive. Technical further develop