This large DryLOK fitting connects the DryLOK port in the bag to the Flow-Rite Qwik-Lok fittings on the end of 1" or 1-1/8" hoses.
This is the male fitting that threads into the bag, you'll also need to purchase the female Flow-Rite fitting (available in straight and elbow versions, see recommended accessories) in order to have a complete connection.