The Sig Sauer M400 Tread is an optics ready, aluminum frame rifle. The Tread features a 16” stainless steel barrel with a free-floating M-LOK handguard, a single-stage polished/hard-coat trigger, ambidextrous controls, a Magpul SL-K 6 position telescoping stock, a mid-length gas system, and is available in 5.56 NATO.