Koolance (patent-pending) quick-disconnect no-spill shutoff valve. 13mm (1/2") ID female swiveling elbow connection with compression fitting. It will fit any Koolance VL3N male shutoff valve.After a quarter twist, the quick-disconnect nozzles will separate. Liquid on both sides will be automatically obstructed with only 0.2mL freed. Nozzles are nickel-plated brass, silicone o-rings.