Safety syringes are disclosed, wherein a needle, at least one locking track and at least one tab disposed on an exterior surface of the barrel, wherein the barrel is in fluid communication with the needle, a plunger capable of fitting into the barrel, and a hollow sleeve having a first opening on a first end and a second opening on an opposite end, and having at least one protrusion on an interior surface of the hollow sleeve, wherein the tab on the at least one locking track on the barrel is adapted to engage the at least one protrusion of the hollow sleeve, thereby locking a position of the barrel with respect to a position of the hollow sleeve.
