By ordering a single part number, you can take all of the guess-work out of getting all of the parts you'll need to install one of the most sophisticated, all-inclusive onboard air systems available today. The Medium Duty Onboard Air System comes complete with a dependable, low amp draw 325C, 33% Duty Cycle compressor at its heart that will fill the supplied 2.5 gallon tank from 110-150 PSI in approximately one minute. Included is everything you'll need to add a reliable single air source to your vehicle. (For vehicles with up to 33-inch tires)