The Xtech Tactical's M&P Shield 9mm +2 Magazine Extender is compatible with factory magazines and installs in seconds. Unlike other extenders on the market, this patent-pending design permits for a consistent internal wall throughout the extender, which is smaller than the magazine tube. The included spring was engineered specifically for the M&P Shield 9mm to allow for unmatched reliability and last round slide hold open. XTech Tactical's MTX line of extenders are simply unmatched for reliability, ease of installation, and durability! Features: Fits all 9mm M&P Shields Adds 2 rounds to the factory 7 and 8 round magazines Uses factory 8 round sleeve when used with the 8 round magazine Tool-free, easy installation Custom engineered spring Optimal ergonomics and texture for recoil control Made in USA Uses factory follower & body (Not Included)