A sealed fluid transfer device comprised of tubing, a proximal fitting, and a distal needle assembly is provided. The needle assembly includes a needle hub secured to a needle cannula. A cantilevered actuator arm extends outwardly from the needle hub having an actuator button at its free end. The needle assembly is disposed in a barrel and can move from a distal position, where the needle is exposed, to a proximal position, where the needle is shielded. The barrel includes a septum which seals the barrel. A spring is disposed in the barrel for propelling the needle assembly to the proximal position. The barrel includes an aperture that receives the actuator button for locking the spring in a compressed condition. Depression of the actuator button enables the spring to propel the needle assembly into its proximal position. A safety mechanism prevents inadvertent depression of the actuator button.