B8 8125 Series Driver or Passenger Side Monotube Threaded Body Shock Absorber (33-225579) by Bilstein. Quantity: 1 per Pack. Designed for the serious off-road enthusiast. Available in multiple lengths for a wide range of custom applications, the 8125 Series features the highest quality machined components for long lasting durability. Gas Pressure Technology. Over time, the mono-tube gas pressure technology developed by BILSTEIN has established itself as a standard in automotive construction. This technology involves keeping the oil in the absorber under pressure, which prevents it from foaming when temperatures and loads are increasing. As a result, full damping power is retained even when the system is placed under extreme stress, a feature that can be observed in the self-lowering piston. Mono-tube Upside-Down Technology. The original and best: The original mono-tube gas pressure shock absorbers bore the BILSTEIN name, and were still responsible for producing the best there is. BILS