YHM has long been a manufacturer of quality AR-15 Upper Receivers and is very proud to offer the popular A3 Upper Receiver. These uppers were designed and machined by Yankee Hill. The top picatinny rail includes M4 Style feed ramps and "T" Markings. The upper will accept mil-spec lower receivers. FeaturesM4 Style feed ramps and "T" MarkingsInside coated with dry film lubeAccepts Standard upper receiver parts (dust covers, forward assists, etc.)Accepts Mil-Spec Lower receiversFit and function with your standard lower receiverHardcoat Anodized matte black to Military Specifications or betterNote: Does not include forward assist or dust cover assembly