Guaranteed to give you an edge, Odin has designed the PMB (Pistol Magazine Base) with the competitive and noncompetitive shooter in mind. Introducing the PMB for Glock: Ergonomically machined to fit perfectly in the palm of your hand for effortless stripping, the weighted base allows for rapid mag changes and 5 extra rounds all while remaining well within the 140 mm gauge limits of USPSA. This mag base is for the Glock 17 (full size 9mm).