6mm ARC caliber; Aircraft grade aluminum receivers; Patented Compact Action; Non-reciprocating side charger; M-Lok free float handguard; Adjustable Gas Block - Never too much and never too little; Features a 1913 Picatinny rail end plate that allows for the attachment of accessories like sling mounts, folding stocks, and more; Mk4 Zeroed parts and accessories - Quality comes standard; Cerakote finish standard; Cmmg's Lifetime Quality Guarantee