The Yankee Hill Machine Co® A3 AR-15 Stripped Upper Receiver is constructed from 7075-T6 aluminum with a corrosion-resistant hardcoat anodized finish. Compatible with Mil-Spec lower receivers, this upper receiver boasts M4 style feedramps for smooth feeding and T-markings on the top Picatinny rail. Stripped upper receiver. Does NOT come with forward assist or dust cover assembly installed. Made in USA.