the end of the bolt path. The butt is closed by an endplate which is held in place by the rear sling swivel. This swivel is attached to a pin which pushes in across the butt and secures the plate. There is a cavity under the buttplate that holds a cleaning kit. Modularity Stock While the AUG is not fully ambidextrous, it can still be configured to be use for left- or right-handed operators by changing the bolt with one that has the extractor and ejector on the appropriate side, and moving the blanking plate to cover the ejection port not in use. However, there exists also a right-hand-only stock that allows for the use of M16 type STANAG magazines. Receivers The AUG's receiver may also be changed from the standard model with a carrying handle and built-in 1.5× optical sight, to the "T" model receiver which has a universal scope mount to allow for the use of a variety of scopes and sights. The rifle also has several different types of receivers with Picatinny rails. Firing mechanism The AUG's firing mechanism may also be changed at will, into a variety of configurations, including semi-auto and full-auto, semi-auto and three-round-burst, semi-auto-only, or any other combination that the user may desire. It may also be converted into an open-bolt full-auto-only mode of fire, which allows for improved cooling and eliminates cook off problems when the AUG is used as a light machine gun or squad automatic weapon. Barrels All AUGs are equipped with quick detachable barrels; including compact barrels, carbine barrels, standard rifle-length barrels and light machine gun barrels. Rifles equipped with pattern barrels produced for military purposes are also equipped with bayonet lugs. The and barrels are capable of launching NATO STANAG type 22 mm rifle grenades from their integral flash hiders without the use of an adapter. AUG barrels can also mount 40 mm M203 or AG36 grenade launchers. Steyr also offers barrel configurations fitted with a fixed, post front-sight used on the standard rifle version with aperture iron sights. Military adoption Australian military The Australian Defence Force (ADF) adopted a modified Steyr AUG designated the F88 Austeyr. From the late 1980s, the F88 became the ADF's standard individual weapon replacing the L1A1 SLR and M16A1 in the Australian Army. From the mid 2010s, the Enhanced F88 (or EF88) Austeyr replaced the F88. The F88 Austeyr was manufactured under