S&W M&P 5.7 introduces the Tempo Barrel System, barrel doesnt cam open until bullet passes gas port. Featuring aslim, optimally textured grip; ambidextrous slide stop; reversible magazine release; slide cut for optics; flat face trigger for consistent finger placement that allows for more accurate and repeatable shooting; Picatinny-style equipment rail and an accurate 1 in 9" twist barrel. Includes two 22-round magazines.