It's an assault rifle. Simple operation, bullpup design. Last time I actually saw one was in the hands of an Australian soldier. They've got some pretty interesting design features, like the quick change barrels. They're decently lightweight, very reliable, and moderately accurate. They operate on a short stroke gas piston, so they don't need to be cleaned as anally as the M16/M4's do. The ergonomics are also pretty sweet on them. Also, like pretty much every other assault rifle in use these days, it's chambered in 5.56 NATO.