Class R connectors are intended for use in enviroment resisting applications, Connector backshells must be installed to meet the specified aoisture sealing requirements.

Class G connectors are intended for use in environment resisting applications that require electric conductivity of the shells. Continuity is provided across the mated connectors from the shield termination area on the plug to the shield termination area on the receptacle.

Class H receptacles are intended for use in applications wherein pressures must be contained by the connectors across walls or panels on which they are mounted.