ZHSYMX 2500 lb Universal Replacement Air Spring Bag 1/2" NPT Air Suspension Spring Double Bellow for Heavy Duty Single Port for Trucks ZHSYMX Rear Air Spring kit is the easy, inexpensive solution to vehicle "bottom out" events, sway and body roll and rough rides that are often the result of inadequate or uneven rear suspension. Consisting of two durable, easy to install and use pressurized cylinders, this kit provides up to 1,000 pounds of load leveling power on each rear wheel, ensuing a safe, smooth and level ride when you need it. 1. Fully adjustable rear air springs level your vehicle when towing or hauling a heavy load for a safe comfortable ride 2. Easily installs inside your vehicle's standard rear coil springs to eliminate sag and bottoming out 3. Rugged durable materials used ensure that air springs and all hardware will last indefinitely under proper conditions 4. Inflatable up to absolute max of 50-psi, with a minimum of 5-psi and provides up to 1,000 pounds of leveling capacity 5. Both air springs can be inflated to the same pressure via a single air line, or can be inflated to differing pressure when needed via a dual air line configuration