That is an Ares-16 AMG with a full-auto lower for the best belt-fed action you can get on this side of an AR-15. It’s not cheap but if you’re picking up toys like these you know what you’re getting into.
Not only does this AR-based machine gun use belts, it can also feed from standard magazines, too. This gun was designed for military use but some people just don’t want to let go of their Minimis.
These are the same people who are working on the “featureless” SCR that we just can’t wait to get a hold of.