This International Standard specifies the essential interface dimensions, as defined in ISO 7241-1, and the operating requirements for hydraulic couplers employed to transmit hydraulic power from agricultural tractors to agricultural machinery. It is applicable to couplers used in hydraulic lines other than those used for braking circuits (see ISO 5676). NOTE All hydraulic couplers need to be connected and disconnected frequently to allow the transfer of machinery from one tractor to another without the use of tools or special devices.