Superior Automotive RideEffex Spacer Coil Spring Rubber Donut - Extra Thick (18-1920) 5" Diameter in the groove, 3" Thick. Provides approx. 2.5" lift. Slit for cutting to fit and winding into the middle of the coil to help restore sagging springs. Do not attempt to place this item at the bottom of the coil. This could cause injury or death. A spring compressor is required for placing donut at the bottom of the spring. DO NOT DO THIS YOURSELF. THIS REQUIRES A LICENSED MECHANIC.