The Troy Sig 556 rifle rail provides the optimum solution to upgrade the standard Sig sights with Troy Folding BattleSights. Accepts all accessories designed for the M1913 Picatinny rail system, including Troy Modular Combat Grip and Troy BattleRail Panels. Installs easily with no special tools. Creates the ultimate Sig 556 rifle. Troy BattleRails are designed to fit Sig 556 receivers with three rail screws. - Weight: 21.47 oz - All NFA Rules Apply. - Troy Folding BattleSights and Medieval Flash Suppressor not included. - Flat Dark Earth