We have a Class A RV and to fill the rear tires takes a chuck that has a somewhat reverse head like this one from Milton. We had an inexpensive inflator I picked up at a local auto parts store and after just a few months of use the hose blew out. I certainly wouldn't want that to happen at a critical point out on the road so it was time to spend a few bucks for a decent quality inflator. I have a few Milton tire gauges I have purchased on Amazon that have been rock solid so this seemed to be right tool for long haul.