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. Technical Specifications Receiver Finish Type 3 Hard Anodized, Black Upper Receiver Material Forged 7075 T6 Aluminum Bolt Carrier Group NOT Included Charging Handle NOT Included Compatibility All AR-15 Calibers, EXCEPT .458 SOCOM Country of Manufacture USA UPC 712038922406