This document establishes the requirements for aircraft@ hydraulic couplings@ self-sealing one side only@ for use in Type II hydraulic systems (-65 to +275 ??temperature range) as defined by MIL-H-5440. the purpose being to connect a hose or tube to a standard MS33655@ MS33514 or MIL-F-85421@ or MIL-F-85720 fitting and to provide the self-sealing feature on the hose or tube side of the connection. Product Classification: Hydraulic self-sealing coupling shall be of the following classes. a. Class 1000: 1000 Ibf/in2 (gage) b. Class 3000: 3000 Ibf/in2 (gage) c. Class 4000: 4000 Ibf/in2 (gage) d. Class 5000: 5000 Ibf/in2 (gage)