The gas helmet worn by the Australian Officer is known as a PH helmet.The tunic is made in Britain in 1916, and follows the pattern of tunic used by combat Officers. The tunic is made of a heavy strong barathea material. It has leather re-inforced cuffs, and a 'gas- collar'. This gas-collar consists of a flap that buttons across the neck of the tunic allowing the collar to close tightly about the neck, thus producing a seal against contamination by gas.

The PH helmet was worn over the head and inside the tunic, the collar was then closed about the lower section of the hood for protection. The PH helmet is constructed of a double layer of light blue-grey flannel, with two glass eye pieces set in metal rims. The 'snout' of the helmet has a metal tube, leading from a rubber mouth piece that is held in the mouth, to the outside of the helmet, where a rubber valve would be usually found (missing on this example). The rubber mouth piece is of an identical design to modern day snorkeling and scuba diving mouth pieces. This helmet was issued with a simple set of
eye shields, which were carried in the hood's haversack. Later a more elaborate set of goggles were issued. The user of this gas hood would be required to breath in through the nose, the air passing through the chemically soaked material hood and he would breath out through the mouth piece.

This PH helmet would be normally be carried in a small cotton haversack, slung from the shoulder. The flap of the bag is secured by two 'plastic' buttons and the shoulder strap is adjustable, by the use of three brass buttons and corresponding button holes.

This gas hood was replaced by a gas mask with a separate box filter. The Gas Mask replaced the PH Helmet. Then, towards the end of the war, when gases that caused blistering were introduced, the PH helmet was reissued and both these protective devices were issued at the same time. The threat of gas attacks were real and in Europe, almost a regular occurrence during a battle, in some of the other theatres of the war gas did not play as great a part, but it was always a constant threat.

The other equipment worn on the tunic is the leather Sam Browne belt equipment, originally used by the British Army from the late 1800s, but officially adopted in this pattern in 1902, being slightly lighter and thinner that some earlier versions. The officer's tunic was tailored made for an officer in the A.I.F. 10th Inf. Battalion, in 1916, by a Saville Rowe tailor.