Features: Effectively solve problem of springs weakness when heavy load and improve performance of shock absorbers Improve driving comfort and more stable during curve corner Reduce pumping of absorbers when passing through road hump or yellow line Reduce noise and vibration during traveling. Protect shock absorbers and suspension system to avoid oil leak. Improve braking efficiency Size for all type of car including lowered spring and adjustable Specification: Material: high quality rubber Suitable models: 90% car can be used How to use: Jack up the car, till the spring be extended totally; clean the spring and then spray some water or oil on it for easy installation; install the shock absorbers Size: Spring gap: 12mm; spring thickness: 15mm; spring diameter: 120mm includes: 4*shock absorbers