The Smith & Wesson Response breaks down barriers for those looking to enter the pistol caliber carbine market. With its innovative FLEXMAGA(R) System, you can use a wide range of double stack 9MM pistol magazines from Smith & WessonA(R) and other manufacturers. Familiar MSR controls make it an easy transition for range day, and with the ability to change parts with existing MSR accessories, it makes optimizing to your needs easy. 16.5" 1:10" twist barrel FLEXMAGA(R) magazine well adapters. (Interchangeable magazine well adapters that let you use a variety of magazines from Smith & Wesson and other manufacturers.) Fixed Stock Non-threaded Muzzle Flat-face trigger with crisp break. M-LOKA(R) slots on handguard with Picatinny-style rail on top. (2) FLEXMAGA(R) magazine well adapters (1-M&P Double stack - installed, 1-G17/G19). Crimson Trace RAIL MASTER Tactical Light - MLOKA(R) accessory rail included