Thanks to a proprietary design developed by the engineering team at Tyrant Designs, owners of Smith & Wesson M&P Shield handguns can extend the capacity of their single-stack defensive pistols with ease! The Tyrant Designs Magazine Extension is one of the easiest-to-install mag extensions made today. Each Tyrant Designs Smith & Wesson M&P Shield Magazine Extension adds two rounds to the overall capacity of an OEM magazine with an incredibly low amount of effort. Each extension can be installed onto your factory Smith & Wesson magazine in fewer than 10 seconds! The Tyrant Designs M&P Shield Magazine Extensions are machined from aerospace-grade aluminum and are designed to function with the original factory magazine spring. The design features smooth, rounded edges, and the overall size matches the profile of you gun's pistol grip. The overall length of the extension is 1.15 inches, and it measures .90 inch wide. The unit will add 1.2 ounces of weight.