features: •quick connation •interchangeable completely between adapter and coupler •pressure-proof hydraulic pressure test 300 psi for up to 4" and 200 psi for 5" and up materials: •stainless steel (investment cast)1/2"-6" •packing: buna-n(nbr) (or teflon, viton on request) specifications: our couplings conform to mil-aa-57326(mil-c-27487) and are interchangeable with other products which meet this specification