Original U.S. Gentex HGU-56/P Rotary Wing Helicopter Helmet with Dual Lenses - Size Large Antique Long Guns and is the correct color

and is the correct color for the period

The best marking however is right over the trigger guard by the grip: 5

"By July 4 [1918]

This is an excellent condition rare WWII HJ Ski Cap in black wool with a sewn on BeVo HJ diamond patch to front

The interior liner denotes the size of the "headpiece" and LARGE  X-LARGE

Original U.S. Gentex HGU-56/P Rotary Wing Helicopter Helmet with Dual Lenses - Size Large Antique Long Guns and is the correct colorOriginal Item: Only One Available. This genuine Gentex HGU 56 P helmet is offered in excellent condition and is a size large. It is a used military surplus helmet. This same model helmet, without communication device, is available new for $1728 at this link. So, this offering is a great deal for collectors. It comes standard with both clear and tinted visors. All Gentex visors are made of polycarbonate and meet all performance requirements of MIL V