Calibers: 5.56 NATO/223; 7.62 NATO/308 Win. It has an LMT Monolithic Rail Platform, MRP upper receivers, and a mil-spec lower. It lacks the ambidextrous controls of the MARS system. S-A bolt carrier group, Defender lower receiver. 14.5" Picatinny top rail, M-LOK-compatible attachment points on other rail faces—low-profile gas block with straight gas tube; textured grip, M4-style stock, and dry-film-lubricant-coated extension tube. Add 25% for the 7.62 16" model.