Triple-Lok® 37° flare tube fittings and adapters are the most popular industrial tube/hose fitting connection in the world. Simply by changing the industry standard sleeve, the same Triple-Lok body can be adapted to metric tubing in sizes ranging from 6 mm tube O.D. to 38 mm tube O.D. Likewise, by using only the body without the nut and sleeve, the Triple-Lok fitting is used as an industry standard hose adapter.