These units replace the magazine base plate and internal locking plate. They do not alter the capacity of the magazine. These units provide better comfort and control by adding approximately 1/2" of gripping surface. (Two extensions per package) These units replace the magazine base plate and internal locking plate. They do not alter the capacity of the magazine. These units provide better comfort and control by adding approximately 1/2 inches of gripping surface. (2 extensions per package). Features: These units blend with the contours and texture of the firearm 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