Bontrager's Air Support HV is a life-saver when you flat out on the trail. A large volume chamber makes it a breeze to use on fat mountain bike tires. It has an easy-to-use thumblock, an auto-selecting head that fits Presta and Schrader valves, plus a fold-out T handle and a dual action for fast inflation. The Air Support HV is compact and light and it comes with a mount to carry it on your frame.