The Koni 1145 Sport Kit 13-17 BMW 335/340i xDrive AWD is a performance suspension upgrade designed to improve the handling and ride quality of BMW 335/340i xDrive AWD vehicles (excluding RWD and EDC models). The kit includes four Koni Sport shock absorbers, four progressive-rate lowering springs, four bump stops, and four spring seats. The shock absorbers feature Koni's patented FSD technology for improved ride comfort and handling. The progressive-rate springs provide improved cornering and better body roll control, while the bump stops and spring seats help reduce suspension noise and improve damping control. This kit is an ideal choice for those looking to upgrade their BMW 335/340i xDrive AWD suspension for improved performance and comfort.