These units replace the magazine base plate. This extension will not alter the capacity of the magazine. They will add approximately 5/8 inches 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. Features: These units blend with the contours and texture of the handgun and have a factory appearance They are made from high impact polymer and withstand drop tests at temperatures from -20 to 350 deg F They provide control and comfort without sacrificing conceal ability