Replaces the magazine floor plate adding grip length (5/8" aprox). Does not increase the capacity of the magazine. Fits 9mm, and 40SW only. For use on XDM ELITE and standard XDM models. Installation of this component requires the removal of the detachable magazine well. ***The 14 round magazines are equipped with a factory installed plus 1 extension. Removing that base and installing this product will make those magazine 13 rounds. Will not fit standard XD frames. Will not work on (10) round XDM magazines with plastic magazine tube spacer.