Dual and Straight Hold on Chuck. Features: Sealing Type Air Chucks employ a "check valve" which seals the chuck, closing the air passage while it is not being used, and when used, it will open the core on the tyre valve, allowing the pressure from the hose to be transferred to the tyre. When a "live" non-gauged airline is used for inflation of the tyre, a sealing air chuck should be used. Ideal for dual rim tyres.