a simple , reliable , low cost hypodermic syringe , comprised generally of a barrel and plunger and including a slidable protective sleeve yieldably retained in an initial retracted position , whereby the capped needle end of the syringe is exposed and a warning band is obscurred . the sleeve is movable after removal of the cap , which had also served as an assembly tool , to an extended latched position , thereby enshrouding the needle , and exposing said warning band . the user can add retentive resistance further opposing premature extension of the sleeve . once the syringe is used the cap can be safely used again to further isolate the needle , within a structurally stable , and permanently extended sleeve .