Firestone W217602528 Ride-Rite Kit for Silverado 2011 and Sierra 2500/3500 Levels vehicle front-to-rear and side-to-side Stabilizes vehicle while loaded and maximizes vehicles load carrying capacity Adjustability is between 5-100 Pascal per square inch Used on pick-ups, class A,B,C motorhomes, vans, commercial vehicles and SUV's Kit includes air springs, air line, fasteners, upper and lower brackets, inflation valves, push-to-connect air fittings and detailed instructions