Original U.S. Vietnam War Helicopter Pilot Gentex APH-5 Helmet by Sierra Engineering Company Ancient which was established as a

which was established as a joint Unified Combatant Command

There is a brass plaques attached to the frame stating:-

The telescope is made of brass with a wood barrel cover and is an early Two draw variety

See BRITISH MILITARY FIREARMS by Howard Blackmore Page 125

Original U.S. Vietnam War Helicopter Pilot Gentex APH-5 Helmet by Sierra Engineering Company Ancient which was established as aOriginal Item: Only One Available. This is a Vietnam War era United States Helicopter Flight Helmet type APH 5 Helmet manufactured by Sierra Engineering Company in size large. The helmet is in overall excellent complete condition with the liner, headset, boom mic, and clear visor. The helmet is maker marked by Sierra Engineering Company and is a size large. This is a rare Vietnam era original rare helicopter helmet in wonderful complete condition! The