Pro Mag Industries AR-15 9mm Magazine Features The ProMag AR-15 Conversion Magazine is molded from a proprietary DuPont Zytel based polymer a durable engineered material chosen specifically for its strength and long-term resistance to cracking under repeated loading and unloading. This polymer construction keeps the magazine lightweight while still standing up to the wear of regular range use. An injection molded follower ensures smooth consistent feeding of 9mm rounds from the first round to the last reducing the chance of a feed malfunction during a string of fire. The magazine s 40-round capacity gives shooters significantly more rounds on tap compared to standard-capacity options cutting down on reload frequency during extended sessions. Inside the magazine a spring formed from heat treated chrome silicon wire provides reliable consistent spring tension across the full capacity of the magazine. This type of wire is chosen specifically for its fatigue resistance meaning the spring maintains its feeding force even after being loaded to capacity repeatedly over time. Designed to fit the standard AR-15 9mm lower receiver this magazine is compatible with a wide range of 9mm AR-15 builds on the market. Manufactured in the USA the ProMag AR-15 Conversion Magazine gives 9mm AR-15 owners a dependable high-capacity option for range day. Pro Mag Industries AR-15 9mm Magazine Specifications Manufacturer: Pro Mag Industries Model: AR-15 9mm Magazine Caliber: 9mm Luger Capacity: 40 Rounds Material: DuPont Zytel Based Polymer Compatible Hosts: AR-15 9mm Conversion Available At: GrabAGun