The Agency Arms 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)
Agency Arms +5 Magazine Extension, Fits Sig Sauer P320 Magazines, Anodized Finish, Black, Aluminum Construction BP-320-BLK