This AR-10 complete .308 rifle length upper has a 20" 416R stainless Heavy barrel, and features a 1:10 twist rate, with a rifle length gas system. It includes a 15" MLOK split rail, an M4 flat-top billet upper receiver, a AR10 bolt carrier group, a flash hider, and a rear charging handle and features the new handguard. This .308 upper is compatible with 1st gen DPMS low profile lowers.