SIG Sauer aimed to do the entry-level AR-15 the right way with the addition of the M400 Tread to its lineup, providing consumers with a rifle built from the ground up to offer the best-possible features at a price anyone can afford. Each SIG Sauer M400 Tread is a cut above what most consumers think of when "entry-level AR-15" springs to mind. Gone are the boilerplate A2 elements. Instead, SIG added a wear- and recoil-reducing mid-length gas system complete with a low-profile gas block hidden under a free-float handguard compatible with all M-LOK accessories. The rifle also features ambidextrous controls, and the barrel is machined from stainless steel. Direct-imping Mfg: Sig Sauer, Inc.