A syringe adapter for a closed fluid transfer system, the syringe adapter including: a housing defining an open distal end and an open proximal end, wherein the housing; defines a pair of opposed longitudinally extending slots opening from the open distal end thereof; and includes a pair of opposed longitudinally extending ribs projecting from an inner surface thereof; a base supported in the open proximal end of the housing and including a syringe adapter luer connector; a needle defining a lumen therethrough, the needle being supported in the base such that the lumen of the needle is in fluid communication with the luer connector; a collar slidably and rotatably supported in the housing, the collar defining: a longitudinal opening therethrough; a pair of opposed L-shaped tracks formed in an outer surface thereof and configured to receive a respective longitudinally extending rib of the housing therein; and a pair of opposed helical tracks opening from a distal surface of the collar, the opposed helical tracks being aligned with a respective slot of the housing when the collar is in a distal-most position; 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, the barrel defining a central opening aligned with the shuttle lumen; a biasing member interposed between the collar and the shuttle for urging the collar away from the shuttle; and a first adapter seal interposed between the shuttle and the barrel, wherein the first adapter seal extends across the shuttle lumen and the central opening of the barrel; and a second adapter seal supported at a proximal end of the shuttle, wherein the second adapter seal extends across the shuttle lumen and the central opening of the barrel, wherein the first adapter seal is movable, together with the shuttle, relative to the collar, from a first position where the first adapter seal is axially external of the collar to a second position, upon axial displacement of the shuttle, where the first adapter seal is axially disposed within the collar. a housing defining an open distal end and an open proximal end, wherein the housing; defines a pair of opposed longitudinally extending slots opening from the open distal end thereof; and includes a pair of opposed longitudinally extending ribs projecting from an inner surface thereof; a base supported in the open proximal end of the housing and including a syringe adapter luer connector; a needle defining a lumen therethrough, the needle being supported in the base such that the lumen of the needle is in fluid communication with the luer connector; a collar slidably and rotatably supported in the housing, the collar defining: a longitudinal opening therethrough; a pair of opposed L-shaped tracks formed in an outer surface thereof and configured to receive a respective longitudinally extending rib of the housing therein; and a pair of opposed helical tracks opening from a distal surface of the collar, the opposed helical tracks being aligned with a respective slot of the housing when the collar is in a distal-most position; a longitudinal opening therethrough; a pair of opposed L-shaped tracks formed in an outer surface thereof and configured to receive a respective longitudinally extending rib of the housing therein; and a pair of opposed helical tracks opening from a distal surface of the collar, the opposed helical tracks being aligned with a respective slot of the housing when the collar is in a distal-most position; 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, the barrel defining a central opening aligned with the shuttle lumen; a biasing member interposed between the collar and the shuttle for urging the collar away from the shuttle; and a first adapter seal interposed between the shuttle and the barrel, wherein the first adapter seal extends across the shuttle lumen and the central opening of the barrel; and a second adapter seal supported at a proximal end of the shuttle, wherein the second adapter seal extends across the shuttle lumen and the central opening of the barrel, wherein the first adapter seal is movable, together with the shuttle, relative to the collar, from a first position where the first adapter seal is axially external of the collar to a second position, upon axial displacement of the shuttle, where the first adapter seal is axially disposed within the collar.