Standard issue United States M1 pattern steel helmet, olive drab in colou, stretch cotton cargo type net, with fibreglass liner. On the inside of a strap in the liner '8415-153-6671' is printed in black ink. This number would appear to be the "Federal Stock Number (FSN)" which was used 1949 to 1975 when ti was replaced by "National Stock Number (NSN)' by additional of 00 after the first 4 numbers. this would indicate that it was made in USA. The chin strap and liner are both complete and fully operable. These helmets were first issued in 1941 to the United States Armed Forces. They were adopted after the Korean War by the Australian Defence Force. In the 1990s they were replaced by the Kevlar based Personnel Armour System-Ground Troop (PASGT) type helmet. However, as evidenced by this helmet, some M1 Steel helmets were not replaced in-service by the PASGT helmet and survived into the early 21st Century. Used by Royal Australian Army in Vietnam in areas where mines were significnat, such as Long Hai's mountains (together with US flak jackets), and also by Royal Australain Navy.An example of an Australian Army issue M1 steel battle helmet complete with fibreglass liner. This helmet type was issued to Australian defence personnel during the Vietnam conflict. The inner line has a transfer on the front " Australian Military Forces" with rising sun badge. The steel outer has an olive green elastic cover (similiar to cargo net) to hold camouflage material. The M1 is two "one-size-fits-all" helmets: an outer shell made of metal and a hard hat-type liner that is nestled inside the shell and contains the suspension system that would be adjusted to fit the wearer's head. Helmet covers and netting would be applied by covering the steel shell with the extra material tucked inside the shell and secured by inserting the liner. The helmet is 7 inches in height, width is 9.5 inches and length is 11 inches. The weight of a World War II era M1 is approximately 2.85 pounds including the liner and chinstrap. (From Wikipepedia) the inner line has a transfer on the front " Australian Military Forces" with rising sun badge.steel helmet

173 AIRBORNE BRIGADE (SEPARATE) US ARMY 1 RAR BATTLE GROUP BIEN HOA 1965-1966 On May 5, 1965, the Brigade deployed to South Viet Nam as the first US Army ground combat unit in that war. Upon arrival, the 1st Battalion of the Royal Australian Regiment (1 RAR) and a battery from New Zealand (161Royal NZ Artillery) were attached to the Brigade -- making the 173d Airborne the only multi-national combat unit in the war. Initially headquartered in Bien Hoa, the Brigade operated in the four provinces around Saigon. (Xuan Loc, Long Khanh, Phuoc Long & Phuoc Tuy), but (in its roll as a "Fire Brigade") also went to the Central Highlands (Pleiku / Kontum) to fight Viet Cong. The 173d also conducted constant operations against the southern stronghold of the VC Main Force in the legendary Iron Triangle in War Zone D. The brigade was organized as a balanced airborne combat force consisting of two infantry battalions, an artillery battalion, a support battalion, an engineer company, a cavalry troop, an armour company, and a headquarters company. Upon activation, it became the first and only separate airborne brigade in the United States Army. This was the beginning of a long series of "Firsts" for the Brigade. On 5 May 1965, it became the first US Army ground combat unit committed to the war in South Vietnam, where further organizational changes were to take place. Australians attached to the Brigade were: 1st Battalion, of the Royal Australian Regiment (I RAR) and support troops of the 4/19th Prince of Wales Light Horse Regiment (1Troop), 105 Field Battery Royal Australian Artillery, 161 Field Battery Royal New Zealand Artillery, 3 Field Troop Royal Australian Engineers, 161 Reconnaissance Flight, Royal Australian Army Air Corps, 1st Australian Logistical Support Company. The Brigade's two infantry battalions, the First Battalion of the 503' Infantry (1/503`d) and the Second Battalion, of the 503`d Infantry (2/503`) and the attached Australians of 1 RAR constituted the infantrymen available to the Brigade. Their mission was to protect the Bien Hoa Air Base and to close with and destroy or capture the enemy. This was in fact the first operational ground force formed under the ANZUS Defence Treaty. ANZUS was a mutual defence treaty signed in 1951 between Australia, New Zealand and the United States of America. In 1965 the spirit of this treaty appeared as 173d Airborne Brigade (Sep) a tri-national brigade. The only such tri-national fighting force formed during the Vietnam War. On deployment to South Vietnam in 1965, 1 Troop A Squadron, 4th/19th Prince of Wales's Light Horse Regiment was part of the US 173rd Airborne Brigade combat group. Flag, two colours divided vertically, hoist half mid blue, fly half red. Badge of 173rd Airborne Brigade (730 x 490 mm) in centreflag, 173rd airborne, south vietnam