This grip extension replaces the magazine floor plate and internal floor plate on the 9mm (13 round only) 40 s&w 375 sig.It adds approximately 1 inch in length and additional capacity.Note: these extensions will not work with the 10 round 9mm magazines the xdm frame or the mod2 frame.Caliber: 9mm LugerCapacity: Springfield XD (Not 45 ACP)Finish: MatteModel: Grip ExtensionMaterial: PolymerModel Fit: XDBrand Fit: Springfield Armory