An excellent example of a genuine U.S. Gentex SPH-4B flight helmet typically used by helicopter pilots. The SPH-4B is one of the most commonly used military helicopter helmets in the field. The helmet shell is a high-strength, lightweight composite reinforced with epoxy resin. The communications system consists of a boom-mounted microphone M-87/AIC, dual earphones, and a communications cord. It has a fully working dual visor system allowing the user to choose either clear visor or tinted visor. The liner is in excellent shape and uses an energy-absorbing system using polystyrene molded to conform to the inside of the helmet shell. This helmet is in excellent condition with typical light usage marks. On the back right side of the helmet case are two vintage plastic tape labels that read '27 Oct 00' (27^th October 2000) and 'NASA 22' indicating this was most probably an ex-NASA used helmet. The helmet retains its original manufactures labels showing a DLA (Defense Logistics Agency) contract number and was made in 1991, this helmet is sized extra-large.