The Eibach Pro-Kit Springs - E10-15-021-19-22 is an adjustable suspension system designed to improve the handling of the Audi A3 Quattro 2.0 TDI. It features a custom-tuned progressive spring design that reduces body roll and provides a more comfortable ride. The kit also includes high-performance shocks and struts for improved performance and ride quality. The Pro-Kit is designed to lower the vehicle's center of gravity, which helps to reduce understeer and improve cornering. It also reduces nose-dive during braking and improves acceleration. The kit is easy to install and comes with all the necessary hardware.