The IMI Defense Lightweight tactical 2 pieces free-floating barrel Rifle length quad rail set, machined from hardened aircraft aluminum, Mil-Std Hard Anodize finish, perfectly tight fit, ultra-slim cross-section, with continuous 12 O’clock rail and full T-marked 1913 Picatinny rails at 3, 6 & 9 O’clock and 5 QD sling swivel ports.