Sig Sauer M400 TREAD, Semi-automatic Pistol, AR, 556NATO, 11.5 Threaded Barrel, Anodized Finish, Black, Pistol Brace, 30 Rounds, 1 Magazine PM400-11B-TRD-V2 The M400-TREAD Pistol features a free-floating M-LOK enhanced handguard that is lightweight yet rigid for extreme control and ease of mounting accessories such as lights and handstops. The lower receiver has an ambidextrous safety for right or left-handed operation and includes an integrated QD mount for easy sling attachment.