Bilson Arms BA-15FC 6mm ARC 18in Forward Complete Upper Assembly Rifle Length 1-7 Twist 5/8-24 TPI Tactical Grey/Graphite Black. 5 in Barrel Profile: Standard Handguard Type: Free-Float Muzzle Device: A2 Flash Hider Condition: New Fabric/Material: 6061-T6 Aluminum Gas Block Journal Size-Diameter: .750 in Handguard Length: 15 in Gun Rail: Picatinny Gun Make: AR Platform Barrel Material: 4140 Chrome Moly Vanadium Bolt Carrier Group Included: MIL-SPEC Charging Handle Included: MIL-SPEC Weight: 5 lb Magazine Included: No Mount Type: M-LOK Features of Bilson Arms 556fc-ua 18 inch Pump Style Forward Charging Upper Assembly Manuf in-house More efficient & ergonomic charging patent pending pump style forward charging action billet aluminum Cerakote finish Package Contents: Bilson Arms 556fc-ua 18 inch Pump Style Forward Charging Upper Assembly Steel Nitride Bcg Bilson Arms A3UFSTB10R1: BA-15FC 6mm ARC 18in Forward Complete Upper Assembly Rifle Length 1-7 Twist 5/8-24 TPI Tactical Grey/Graphite Black