This grip extension replaces the magazine base plate.It does not alter the capacity of the magazine but, adds approximately 5/8 inch additional gripping surface.Note: this extension will fit the xdm 45 and the mod 2 45 models, however the checkering pattern across the front of the extension will not match the checkering pattern on these frames.This unit will not fit the springfield xds 45.Caliber: 45 ACPCapacity: Springfield XD/V10, Para Warthog, 45 ACP onlyModel: Grip ExtensionMaterial: PolymerModel Fit: XD Mod.2Brand Fit: Springfield Armory