The lower receiver and barrel on this rifle is marked 5.56 NATO, so it will accept and fire both .223 and 5.56 cartridges. The left side of the receiver is marked “Colt Law Enforcement Carbine” and the right side says “Restricted Military/Government Law Enforcement Use Only” just below the ejection port. This AR-15 has a 4-position adjustable M4 stock and A2 style pistol grip. It also has the original 6.5-inch A2 style handguard. This example has the triangle shaped front sight with the bayonet lug underneath.