Coupling with Stop, Tube Fitting Material Wrot Copper, Fitting Connection Type C x C, Tube Size 1/2 in, Outside Dia. 5/8 in, Max. Pressure 577 psi @ 200 Degrees F, Temp. Range -20 Degrees to 400 Degrees F, Standards ASTM B75 Alloy C12200; Third-party Certified To NSF/ANSI 61 Annex G; ASME B16.22; MSS SP-104; NFPA 99 Health Care Facilities Gas And Vacuum Systems And The Compressed Gas Association, Pamphlet G4.1 (Medical Gas)