I meet a guy in Indio, Ca. in 11-2005 at a RV Park who was inflating his coach tires with a powertank.com . He was a distributor for the product. I purchased a 15# Tank and all the accessories for the use of it. I had the tank filled with Nitrogen, MY choice. It was amazing. Filled coach tires from 105# to 110# in less than -1- minute. I installed it in the coach basement, with quick disconnects, and used a 50' hose to air up the coach and toad from either side of the coach. The tank of nitrogen would last 1 to 1-1/2 years between refills, costing between 12-14$ at Gas Supply businesses around the country as we were Full Timers. I paid 495$ for it, and Sold it in Spring of 2014 for 350$. I would do it again .