UNUSED - still in the box it was shipped in. My loss is your gain. Bought the full system from DPS-Performance about 8 mos ago and never found the time to install it. I researched all of the systems out there before buying this one and in my opinion, this one was the best of the bunch for diesel trucks. It is a two-stage, pressure engaged unit with a heavy-duty, high pressure pump. It comes with everything listed in the link below INCLUDING the 8 gallon, bed-mount tank. http://www.dps-performance.com/h2o_system.html I paid $595 plus s/h. $450 obo plus actual shipping costs.