The Air Lift 57291 LoadLifter 5000 Air Spring Kit is built to handle the toughest jobs â whether hauling heavy cargo or towing trailers â with massive support and adjustability. Its leaf-spring design integrates seamlessly with your suspension, restoring balance and control as the load grows.• Offers up to 5, 000 lbs. of load-leveling capacity*• Air springs are fully adjustable to match load and road conditions• Designed for vehicles with leaf-spring suspensions including full-size trucks and vans• Includes roll plates to protect the air springs from damage• Most kits install with no frame drilling required• Improves handling, braking, and steering response by maintaining ride height• Ideal for serious towing, heavy cargo, or commercial applications• Fits 1999-2007 Ford F-Series Super-Duty* Do not exceed the vehicle manufacturer's Gross Vehicle Weight Rating (GVWR).SpecsWeight: 42.5 lbs. Dimensions: 16"W x 12"D x 9"HMount Location: Side FrameApplication Type: Rear Kit Offers up to 5, 000 lbs. of load-leveling capacity Air springs are fully adjustable to match load & road conditions Includes roll plates to protect the air springs from damage