12V DC powered onboard air compressor, tank, filter/water trap, four valves, and valve controller (dash mounted, w/ psi readout dials), is a "plug and play" complete kit with all hoses, hardware, and complete instructions needed for installation. This kit is designed to control/adjust airbag suspension systems on trucks right from the drivers seat. Delivers up to 150 psi compressed air through four separate valves to four airbags (airbags not included), but could also be used for any kind of on demand air supply system for your work truck, onboard tire inflation, etc. Drop and raise entire vehicle with out leaving the drivers seat - hook up to trailers without even using the trailer jack, tune/level vehicle on the go for towing and load leveling, etc. Kit currently retails for $799. This is a brand new unused earlier version from 2009 that came with my F250 when I bought the truck. I just haven't gotten around to installing it. A screaming deal at $150 obo (plus actual shipping), but it's been sitting in the closet for too long - time to pass it on to someone who will make good use of it. Happy to answer any questions.