The M400 Tread is SIG Sauer's direct-impingement AR-15 for the consumer market, featuring an M-LOK handguard, 16-inch barrel, adjustable stock, and ambidextrous bolt release. Positioned as a value-tier entry into the SIG AR lineup, the M400 Tread is manufactured to mil-spec tolerances with SIG QC standards at a competitive price point. Popular with first-time AR buyers who want SIG quality without MCX pricing. Type: Rifle Action: Semi-Automatic Caliber: 5.56x45mm NATO Capacity: 30 Year introduced: 2018, USA Weight: 7.1 oz Overall length: 35" Status: Active Intended use: hunting, home_defense, sport, patrol