Porsche's active sway bar system doesn't play well with most aftermarket coilovers - swap in a fixed-geometry coilover without accounting for it, and you lose the factory system's ability to actively manage roll stiffness. Bilstein's B1 Sway Bar Adapter Kit exists specifically to solve that problem: it lets a Bilstein ride-height adjustable coilover go on a 911 equipped with the active sway bar system while keeping that system fully functional. This is a components-level part, not a damper or spring - it's the piece that makes a Bilstein coilover installation compatible with the factory active roll control hardware rather than working around it. Important Compatibility Information Bilstein publishes this adapter kit for use alongside a Bilstein ride-height adjustable coilover kit on 911 models equipped with the factory active sway bar system. What's Included Sway Bar Adapter Kit components, sized for the active sway bar system Installation instructions Product Specifications SKU: B009 11-239680 MPN: 11-239680 GTIN: 651860741017 Manufacturer: Bilstein Series: B1 (Components) Finish: Galvanized Fits the 2013-2017 Porsche 911 Frequently Asked Questions Do I need this if my 911 doesn't have the active sway bar system?No, this kit is only needed on cars equipped with Porsche's factory active sway bar system. Does this work with any coilover, or only Bilstein's?Bilstein publishes this kit for use with Bilstein ride-height adjustable coilover kits specifically. Will installing this affect the active sway bar's function?No - the purpose of this kit is to retain full functionality of the factory active sway bar system after a coilover install.