Koolance (patent-pending) quick-disconnect no-spill shutoff valve. 10mm (3/8") ID, 16mm (5/8") OD (common Tygon tubing size) female straight 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. Nozzles are nickel-plated brass, silicone o-rings.