Magpul Industries Magazine, AMAG 17 SG9, 9MM, 17 Rounds, For Sig P320, Stainless Steel Finish, Silver MAG1331-SST When polymer won't work" Magpul's AMAGs will. The same reliability and consistency you expect out of their PMAGs" now available in alloy magazines. The AMAG 17 SG9 is a 17-round SIG P320 9mm handgun magazine featuring a heat-treated" stainless-steel alloy body with polymer sub-components. Magpul AMAGs come with many of their proven features" including a high-visibility" controlled-tilt follower" stainless-steel spring" flared floorplate that's easily removable for cleaning and routine maintenance" paint-pen dot matrix for magazine marking" and capacity-indicator windows which begin at five (5) rounds" and continue along the spine of the magazine in one-round increments.