Bilstein B12 (Pro-Kit) suspension kits are a complete set of B8 Performance Plus dampers paired with Eibach (Pro-Kit) springs that provide moderate lowering between 24-40mm (depending on application). These kits offer dampers and springs that are tuned for each specific application to provide the best fixed height lowering solution. Bilstein B12 (Pro-Kit) suspension kits provide the perfect combination of suspension dynamics, quality and aesthetics. Bilstein B12 (Pro-Kit) suspension kits are a complete set of B8 Performance Plus dampers paired with Eibach (Pro-Kit) springs that provide moderate lowering between 24-40mm (depending on application). These kits offer dampers and springs that are tuned for each specific application to p rovide the best fixed height lowering solution. Bilstein B12 (Pro-Kit) suspension kits provide the perfect combination of suspension dynamics, quality and aesthetics.