A closed fluid transfer system for fluidly interconnecting a syringe to any one of a patient I.V. set, a vial and an I.V. bag, is provided and includes a housing defining an open distal end and an open proximal end, a base supported in the open proximal end of the housing and including a syringe adapter luer connector, a collar slidably and rotatably supported in the housing, the collar defining a longitudinal opening therethrough, a shuttle slidably extending through longitudinal opening of the collar, the shuttle defining a shuttle lumen extending longitudinally therethrough, a barrel supported on and extending over a distal end of the shuttle, a biasing member interposed between the collar and the shuttle for urging the collar away from the shuttle, and a seal interposed between the shuttle and the barrel, wherein the seal extends across the shuttle lumen and the central opening of the barrel.