ProTool Pro-Tool Brass Lock-On Tire Chuck-Angled, Silver Professional choice for easy tire inflation; excellent quality, made in Taiwan Must have accessory for auto, heavy-equipment, truck shops; also available in straight-on style Spring-loaded clip locks on to valve stem - since you've got better things to do than hold a chuck Angled design reduces strain on valve stem & hose; great for quick access stems; closed-type chuck Heavy-duty solid brass with galvanized steel lock mechanism, female-threaded 1/4Npt inlet