Harrington & Richardson Early 604 "Air Force" Complete Upper Receiver, 1/12 Twist, Gray.

CMMG Resolute Mk4 AR-15 Complete Upper Receiver 350 Legend 16.1" Barrel

Rise Armament Compete Upper Grey .22 ARC 18 Barrel

Spike s Tactical 16-inch AR-15 Complete Upper 5.56 NATO M4 LE with 9-inch Rail

Spikes Tactical ST-15 Enhanced Mid-Length Complete Upper 5.56 / .223 Rem 16-inch CHF

Rise Armament AR-15 Complete Upper Receiver 22 ARC 18" Barrel 15" M-LOK Handguard Rifle Length Black

Rise Armament AR-15 Complete Upper Receiver 22 ARC 18" Barrel 15" M-LOK Handguard Rifle Length Patriot Brown

Rise Armament AR-15 Complete Upper Receiver 6mm ARC 18" Barrel 15" M-LOK Handguard Rifle Length Black