SAE J3068 is a recommendation published by SAE International which covers the general physical, electrical, functional, testing, and performance requirements for conductive power transfer to medium  and heavy duty Electric Vehicles using a Coupler capable of, but not limited to, transferring three-phase AC power. It defines a conductive power transfer method including the digital communication system. It also covers the functional and dimensional requirements for the Electric Vehicle Inlet, Supply Equipment Connector, and mating housings and contacts.