CLOSED FLOW - Closed flow tire chuck is designed with a shut-off valve inside that means the air will not pass through until you slide down the sleeve of chuck, providing tight seal that will never leak even under high pressure. | LOCK-ON - The air chuck is locking the valve stem when the sleeve is pushed forward while it is releasing when the sleeve is pulled back. Just use one hand to seal and release the chuck. | EASY TO USE - keep your hands free while the tire inflates. The lock on tire chuck make it fix onto the valve stem so you do not need to hold it all the time. It is much easier and faster for using than other chucks. | HEAVY DUTY - It is constructed with 3 parts from top to bottom: top nut, pivot and sleeve. The top nut is made of solid brass for connecting the tire inflator. And the other 2 parts are made of iron. The inside three claws are nickel plating to protect them from oxidation. | WIDELY APPLICATION - The top thread, 1/4 inch FNPT, fits for most tire gauge inflators in the market. Standard bore is available for Jeep, Off-road, Trucks and so on. The Max working pressure is 150PSI.