Agency Arms +5 Magazine Extension, Fits Sig Sauer P320 Magazines, Aluminum Construction, Anodized Finish, Olive Drag Green, Sage Dynamics Engraving BP-320-SAGE The Sage Dynamics x Agency Arms SIG P320 9mm +5 base pad for 17rd magazines. This base pad is specifically designed for the 17rd magazine and is compatible with the Agency Arms X-Series Magwell and the factory magwell from SIG. (THIS BASE PAD IS NOT COMPATIBLE WITH THE AXG MAGWELL)