Magpul MAG1331-SST P320 SG9 17rd 9mm Fits Sig P320/M17/M18 Compatible w/ Full Size/Compact/Sub-Compact Stainless Steel $33.20
Pearce Grip PG365 Grip Extension made of Polymer with Texture Black Finish & 5/8" Gripping Surface for Sig P365 with 10rd Mags $7.46