Customers should be aware of the very high possibility of air loss while driving. The bad thing about all of this is that you lose air so quickly that you have a very small window to drive your vehicle. I wish O could return this as I bought two sets for two campers. I would not recommend an RV owner to buy one. Instead, buy a hubcap removal tool and check the inflation air that way. I was stuck on the freeway at 1:45 am with a flat tire. After calling the curb and getting a 4 hour ETA for a $450 tire change. I decided to get some air to get the van to safety. Luckily I found that the valve extension had been lost. After removing the extension cords, I pumped up some air and drove to the nearest gas station to fill up. I'd pay $450 for a stupid valve extension problem. I took them all off. Do not buy this useless item.