Firestone Air Command- Air Control System, Single Leveling, Heavy Duty, Analog. Air Command- Air Control Systems increase the convenience of air adjustable systems by allowing drivers to adjust the ride for various load and road conditions at the flip of a switch or even a click on a remote. Heavy Duty: 2 year warranty, includes 9499 Compressor, best for 8-lug trucks, trailers larger than 20', slide-in campers and heavy loads. Xtra: 2 year warranty, includes 9499 Compressor, Half-Gallon Air Tank and 9006 Air Hose, best usage same as Heavy Duty, plus motorcycle tire, golf cart tire or trailer tire inflation. ^Includes: Heavy Duty 150 PSI air compressor (9499) Plastic analog control panel 1/4" air line tubing All hardware needed for install 2 year warranty