The HexOne(TM) Buffer Tube is CNC machined from US Certified 7075 T7 billet aluminum. These HexOne(TM) Buffer Tubes feature a new Hex design and include machined scallops that add style to this heavy-duty and extremely rugged component. The HexOne(TM) undergoes an additional surface tumbling process that toughens the outer edges and surfaces yet leaves everything smooth and snag free. Simple, sleek, tough as hell and perfect for 5.56NATO/.223 or 300blk.Edge to Edge OD: 1.4in.Flat to Flat OD: 1.25in.**This model of the Hex Tube lineup is not designed to accept a Stabilizing Brace.Includes:HexOne Buffer TubeCastle NutEnd PlateCarbine Buffer - Standard 3ozPhase 5 Enhanced Buffer Spring