Description Sleeve Type Couplers â Sleeve type couplers require pull-back on sleeve to connect and disconnect plug. They meet dimensional and interchangeability requirements of MIL-C-4109F. When disconnected, coupler body valve shuts off air flow and automatically opens valve when recoupled. Push-on hose barb couplers are for use with push-on hose. Unlike standard hose barbs, no crimped ferrule or clamps are necessary.