Caliber: 5.56 NATO/.223., 6.8 SPC, 300 BLK. Non-NFA Barrels: 14.5″, 16″, or 18″. Weight: 7.4 lbs. Lengths: 34.75” to 37.85″ overall. Stock: Glass-filled polymer with SoftTouch overmolding. Sights: None. Features: Lower receiver is mil-spec with enhanced and flared magazine well, QD swivel attachment point. Upper receiver has M4 feed ramps. Lower and upper CNC machined of 7075-T6 aluminum, hard coat anodized. Add $190 for Cerakote finishes added in 2023.