Agency Arms +5 Magazine Extension, Fits Glock 17/22 Magazines Only, Aluminum Construction, Anodized Finish, Olive Drab Green, Sage Dynamics Engraving BP-G17-SAGE The Sage Dynamics x Agency Arms G17 9mm +5 base pad for 17rd magazines. This base pad is specifically designed for the 17rd magazines. It is not compatible on reduced capacity magazines.