The rail mounted BUISs are Knight’s Armament Corporation Flip Up Front Sight and the Micro Flip Up Rear Sight. Iron sights are peep hole types with a blade and protecting ears on the front sight. The rear sight is graduated from 200-600 meters with a Z setting for zeroing adjustments. Note USMC marked on front end. Also see the two pins on charging handle that can switch the lever to either side. Sling mounts are ambidextrous as is seen from this angle.