the needle protection holder encloses an automatically retractable safety syringe and needle within a tubular cylinder after the needle has been used . its intended purpose is to remove a needle attached to a syringe from a patient , both human and animal , thereby containing the needle safely within the holder or cylinder . with such a construction , the holder prevents the exchange of bodily fluids caused by needle sticks which are known to cause serious illnesses including death to medical technicians and personnel .