RISE Armament AR-15 Complete Upper Receiver 22 ARC 18 in Patriot Brown. Specifications for RISE Armament AR-15 22 ARC 18 inch Complete Upper Receiver: Manufacturer: RISE Armament Caliber: .22 ARC (Advanced Rifle Cartridge) Overall Length: 26 in Barrel Length: 18 in Gas System Length: Rifle Length Barrel Twist Rate: 1-7 Threads per Inch: 1/2x28 Handguard Type: Free-Float Muzzle Device: Thread Protector Fabric/Material: Stainless Steel Handguard Length: 15.25 in Gun Type: Rifle Gun Make: AR Platform Gun Model: AR-15 Barrel Material: Steel Magazine Included: No Features of RISE Armament AR-15 22 ARC 18 inch Complete Upper Receiver Barrel: 18-inch 416R stainless steel button-rifled air-gauged and tested; threaded Handguard: Free-floating skeletonized aluminum with continuous 12 oclock Picatinny rail MLOK slots four threaded steel sling swivel QD inserts a snag-free front and patent-pending attachment lock to maintain your zero Charging Handle: RISE ambidextrous charging handle for right- or left-handed operation and improved ease of use with optics and gloves Bolt Carrier Group: Premium BCG with 9310 bolt individually MPI tested staked gas key durable black nitride finish Receiver: Forged aluminum Package Contents: RISE Armament AR-15 22 ARC 18 inch Complete Upper Receiver What firearm models does the manufacturer say RISE Armament AR-15 22 ARC 18 inch Complete Upper Receiver is compatible with? The manufacturer says that RISE Armament AR-15 22 ARC 18 inch Complete Upper Receiver is compatible with AR-15RISE Armament RA-22ARC-CU-BRN-18: AR-15 Complete Upper Receiver 22 ARC 18 in Patriot Brown