Calibers: 5.56 NATO; 7.62x51. Come with LMT Monolithic Rail Platform, MRP upper receivers, mil-spec lower. Lacks ambidextrous controls of 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. Values for DEFENDER-L 5.56 16 in. Add 27% for DEFENDER-H 7.62 16 in. SEE POLITICAL PANIC PRICING.