Air springs fully adjustable from 5-35 PSI on most applications, helping to level the vehicle when towing or hauling a heavy load for a safe, comfortable ride; No frame drilling required; Helps eliminate sag and bottoming out; Rugged durable components including air springs and all hardware; Easy to install in 2 hours or less with included instructions; Air bags easily fit into the coil springs of coil-sprung vehicles, the most versatile of Air Lifts applications; Features Air Lifts Lifetime Warranty, with a 60-Day Ride Satisfaction Guarantee