Pro M<ag grip spacer allows Glock 17/22 magazines to be used in Glock 26/27 pistols. The spacer takes up the space between the bottom of the frame and the floor plate of the longer magazines. It is held in place by a single Allen-head cap-screw and is textured to match the Glock pistol frame. The spacer is constructed from injection-molded polymer. NOTE: This item is not compatible with Gen 4 Glock pistols.