Bilstein B8 Performance Plus (DampTronic) dampers are a performance upgrade to OE dampers designed to be paired with aftermarket lowering springs. All of the active features of the factory electronic suspension, along with the factory controls, will be retained with the installation of these dampers. Each damper is rigorously tested for quality that meets or exceeds OE standards and features application specific valve settings with a monotube design to bring out the best handling performance of a vehicle. B8 Performance Plus (DampTronic) dampers are the ideal solution for pairing with a lowering spring for improved handling and sportier look in a package compatible with factory electronic damping control. Porsche 911 2011-2005