DPCU (Disruptive Pattern Camoflague Uniform) Brassard for a Sergeant in the Australian Army. 

The Brassard was usually issued to service personel prior to leaving Australia.  A Brassard is an armband attached at the top to the lapel and worn around the upper arm.  The brassard usually carries Unit, role or rank and can be switched easily between items with no sewing required.