These floor plates add two (+2) additional rounds to the factory Glock magazines in 9mm, and one (+1) additional round in magazines in .40 S&W. The floor plates provide an additional gripping surface for more positive control of the pistol. No permanent modification required. Constructed of black injected molded polymer. 2 pack. Features: (2) floor plates for factory Glock magazines Adds +2 additional rounds to Glock 9mm magazines Adds +1 additional rounds to Glock 40 S&W magazines Made of injected molded black polymer Provides additional gripping surface for more positive control of the pistol Made in USA