Old fashioned automatic level systems use a lever between the frame and the axle to determine level and ride height. Most competitive levers are hard to mount and calibrate, and prone to failure. Now Air Lift solves the problem with SmartAir, an exclusive automatic leveling system that has no contact arm. This on board air compressor system inflates, maintains, and controls air springs on your vehicle for maximum convenience and leveling on-the-go. SmartAir does not work with coil-sprung vehicles or Air Lift 1000 adjustable air helper springs.