A fluid collection or infusion set is provided. The set includes flexible tubing with a fitting attached to a proximal end and a needle assembly attached to the distal end. The needle assembly includes a needle hub and a needle cannula secured in the hub. An actuator arm extends proximally and outwardly from the needle hub and has 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 cannula is exposed to a proximal position where the needle cannula is shielded. A spring is disposed in the barrel for propelling the needle assembly to the proximal position. The barrel includes an actuating 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 shielded position.