SMI 31 - Introducing the new PROMAG SMI 31, a 9-round magazine for the Smith & Wesson Shield in .40 caliber. Constructed from heat-treated blued-steel, components molded from ourproprietary TECHNAPOLYMER and our anti-fatigue spring, so you can keep the magazineloaded and ready for up to six years without concern. Promag's magazines are made in Phoenix, Arizona.
- Fits: Smith & Wesson Shield
- Caliber: .40 S&W
- Capacity: 9 Rounds
- Finish: Blued
- Material: Heat-Treated Steel and Technapolymer