XTech Tactical MTX M&P Shield 9mm 2 Round/.40 1 Round Magazine Extension, Black, 1, XTT125-BLK SHIELD MTX

40 S&W. Designed for EDC duty or tactical use this patented extension ensures flawless feeding and installs in seconds. Compatible with factory magazines it features a consistent internal wall and includes a custom-engineered spring for 9mm models ensuring reliability and last-round slide hold open.