Sig Sauer M400, Tread V2, Semi-automatic Rifle, AR, 223 Remington/556NATO, 16 Stainless Steel Barrel, Flash Hider, Mid-Length Gas System, Cerakote Finish, Moss Green, Sig Sauer Grip, Magpul SL-K Stock, Free Float M-LOK Enhanced Handguard, SIG Matchlite 2 Stage Trigger, 30 Rounds, 1 Magazine RM400-16B-TRD-V2G The M400 TREAD V2 is an optics ready, aluminum frame rifle. The TREAD features a 16" stainless steel barrel with a free-floating M-LOK handguard, a SIG Matchlite 2 Stage Trigger, ambidextrous controls, a Magpul SL-K 6 position telescoping stock, a mid-length gas system, and is available in 5.56 NATO.