Dealer's choice. Spike’s Tactical 14.5” Lightweight CMV 1:7 Twist, Mil-Spec cold hammer forged lightweight Barrel 16". Pinned and welded Spike's Dynacomp. ST-T-2 Tungsten Buffer. Nickel boron carrier group. 12" Spike's SAR3 Quad Rail, 1:7 twist. MBUS Magpul sights and 6 position collapsible stock. Spike's life time warranty.