The fittings covered by this specification are military unique because they must be reusable; able to operate satisfactorily in high-temperature fuel, lubricating oil, and water-alcohol systems and in hydraulic and pneumatic systems in an environment ranging from −65 to +450°F (class 1 fittings) and to 275°F (class 2 fittings) at the operating pressures specified in table II; and capable of being mated with polytetrafluoroethylene hose conforming to MIL-DTL-27267 to form hose assemblies conforming to MIL-DTL-25579. High-pressure pneumatic storage system applications are not recommended.