This Air Lift replacement cylinder is an exact replacement for an original Air Lift 1000 air spring. It is made with sturdy urethane construction and the air fitting is molded in to the spring. This cylinder has a diameter of 4.5 inches and a height of 9 inches. Air Lift replacement cylinders are designed to maintain and/or restore the vehicle to the original ride height. The cylinder should be matched to both the inside diameter and inside height of the vehicle spring at normal ride height. It is better to be slightly undersized rather than oversized.