Elite Tactical Systems Group Elite Tactical Systems Group, Magazine, 9MM, 21 Rounds, Fits Sig Sauer P320, Polymer, Clear, Competition Legal 140mm SG9-320-21 ETS magazines are made from advanced polymers that provide extreme impact resistance so they won't crack or break when dropped. With superior temperature tolerances ETS magazines won't become brittle over time" even when exposed to harsh environments" chemicals" or extreme cold. Its durable construction eliminates creep so the feed lips and body won't spread when being stored long term" even when fully loaded.