When youre looking for Maxim Defense ingenuity in a new standard AR-9, the MD-9 is your answer. The MD-9 was engineered to fit the growing demand for cutting-edge AR9 style rifles for todays Military and commercial market.For increased comfort and versatility every MDX features our free-floating barrel with our custom handguard. These handguards provide a monolithic-like upper receiver platform and M-Slot compatibility.FEATURESFlash hider.M-Rax and M-Slot compatible handguard.Military grade materials.5.8 barrel.ALG Combat trigger.Radian charging handle and selector.Maxim CQB brace.Ambidextrous magazine release.Fully floated barrel.Last round hold open.