Air Lift1000 Rear Air Helper Spring Kit 60925 by Air Lift. Set of two adjustable secondary air helper springs designed to mount inside your existing coil springs and add up to 1,000 pounds of leveling capacity for heavy loads. Adds ride comfort and restores proper handling and safety. Air pressure in the springs can be manually adjusted between 5 and 90 psi. Features. Set of two springs support designed to fit within the center of coil springs. Both helper air springs add up to 1000 pounds of leveling capacity per axle. Prevents vehicles main springs from sagging due to constant load compression. Helps reduce bouncing at the rear of vehicle when towing. Air springs can be adjusted between 5 90 psiSpecifications. Spring Diameter 5.5 in.. Length 9.5 in.