The AM-15 Stripped Upper Receiver is machined from 7075 T6 Aluminum forging. Featuring M4 feed ramps this upper receiver is machined to Military Specifications & Standards and can be used with multiple calibers on the AR-15 platform. This upper receiver comes in type III hard coat black anodize. Match this Upper with one of our Lower Receivers for a solid fit for your AM-15 build. - FEATURES: Mil Spec Standard - MATERIAL: 7075 T6 Aluminum Forging - FINISH: Type 3 Hard Anodized Black - COMPATIBILITY: All AR-15 Calibers except .458 SOCOM - TREATMENT: Non RF85