Smith & Wesson Response, Semi-automatic, AR, 9MM, 16.5 Barrel, Threaded 1/2x28, Black Oxide Finish, Black, Polymer Upper/Lower Receiver, M&P Grips, Free Float M-LOK Handguard, Collapsible Stock, 23 Rounds, 2 M&P Magazines, 2 FLEXMAG Adaptors For GLOCK and Smith & Wesson Magazines 13797 The Smith & Wesson Response breaks barriers for those looking to enter the pistol caliber carbine market. With its innovative Flexmag System, you can use a wide range of double stack 9MM pistol magazines from Smith & Wesson and other manufacturers. The familiar MSR controls make it an easy transition for those looking to use on the range, and with the ability to change parts with existing MSR accessories, it makes optimizing to your needs easy. Take control with the new Smith & Wesson Response!