The M&P15 Defender is a home-defense-oriented AR-15 with a 16-inch barrel, six-position stock, and Magpul MBUS backup sights included from the factory. Features a 1:9 twist chrome-lined barrel and standard direct-impingement carbine-length gas system. Marketed primarily to home defenders seeking a proven semi-automatic rifle platform with reliable iron sights from the factory rather than requiring additional optic purchases. Type: Rifle Action: Semi-Automatic Caliber: 5.56 NATO Capacity: 30 Year introduced: 2012, USA Weight: 6.5 oz Overall length: 35" Status: Discontinued Intended use: Home Defense, Sport Shooting