Abstract: A needle protective assembly includes a ratchet and pawl arrangement for permitting the unidirectional movement of a protective sleeve along a body of a dispenser, such as a hypodermic syringe. The sleeve is adapted to cover a standard Y-site diaphragm, and includes a lock to secure the sleeve to the Y-site while in use. The assembly may also include indicia on the exterior thereof to measure the amount of needle exposed beyond the end of the sleeve, if the sleeve is not in its fully extended position. The assembly may further include a luer lock, for attaching the assembly to pre-existing standardized fittings.