7/9/10/12/13.5/15'' unique olive green anodized keymod handguard rail with 3 x picatinny / weaver rail sections aluminum

barrel nut threads spec.: 1-1/4-18 unc barrel nut inside diameter : 1.02'' ( 26 mm) barrel nut outside diameter : 1.35'' (34.4 mm ) one piece ultralight key mod nsr handgaurd rail system package included: 1 x handguard + allen key + aluminum barrel nut + shims + screws +3 pcs rail sections