The US Army developed a square water canteen for service in Vietnam. It held two quarts of water and could be squashed down when not in use to take up less space. The design was introduced in the late 1960s and the Australians quickly adopted examples for its military as the extra water capacity was always needed. When the new Auscam uniform and webbing was introduced in the late 1980s a square collapsible canteen with Auscam cover was also produced:

A number of variations of this canteen and cover can be found, but this is one of the earlier patterns, dating from the early 1990s. This early auscam weathers to quite a muted pattern, as can be seen here. The cover secures with a plastic press catch:

A small pocket is sewn to the front with a velcroed flap that can be used to carry water purification tabs:

The back of the cover has a strip of woven cotton webbing which can be used to hold a pair of belt clips to allow it to be carried as part of a webbing set:

Alternatively a shoulder strap can be attached to the pair of plastic buckles on either end of the cover:

A large label is secured to the inside of the cover which dates it to 1994:

Note also the felt lining to the cover which helps to insulate its contents and keep the water inside the canteen cool.

The canteen itself copies American practice and is square in shape, with the spout at one corner

A central panel has the /|\ property mark, an NSN number and date of manufacture:

These water bottles and their covers seem to have been pretty popular and production continued into the 2010s, albeit with some updates to the covers themselves. They are often seen on photographs attached to either the webbing, the rucksack or slung around the body to give the Digger some extra water capacity.