As has been discussed on the blog before, the Australian Disruptive Pattern Camouflage Uniform came in two prototype cuts and four production cuts over its lengthy service life. Alongside the updates to the uniform design, at each update subtle changes were made to the accompanying bush hats as well as differing widths of brim. Although British troops like short brims to their bush hats, the Australians seem to have been more open to wider designs and both short and broad brimmed hats are seen being worn alongside each other. This is an example of the broad brimmed variety:
The broad brim is quite clear on this example. Other features of this hat include a drawstring to go under the chin to prevent the hat blowing off and a piece of flannel to absorb sweat inside the top and back of the crown:
Loops are fitted around the crown to allow foliage to be attached and button hole openings are sewn in to aid ventilation:
A printed label is sewn into the hat, however these are frequently very worn as they are subject to a lot of wear and sweat which slowly removes the printing on them:
This is one of four Auscam bush hats in my collection and each one is different, showing the wide variety in Australian uniforms and the joy of collecting is tracking down each version to add to the collection.
Tales from the Supply Depot 
I am surprised to see no side-snaps. Other hats have them, and would permit the hat to be worn in iconic slouch hat Aussie-style. Ah well, easily fixed with a stitch of thread.
Narrower brim hats are referred to as “bucket hats” in US parlance. They are more regular in appearance but protect less well against sun and rain. I insert a (plastic) wire near the edge to prevent broad brims from drooping over the eyes.
— Robert in Houston
The drawstring doesn’t go under the chin, it actually goes around the back of the head and is tightened so the hat cannot be blown off in a strong wind.
Under the chin is actually a choking hazard if the hat becomes snared in low branches.
Another version of this bush hat has a smaller brim and was known as the “boonie” other names include “giggle hat” and “roofing nail” as they made the wearer look like a giant roofing nail with such a large brim.
I served 14 years in the Australian Army and still have my bush hat in my vehicle and wear it while camping.