Product Description The LanTac UAR Billet Upper Receiver is a precision-engineered AR-15 stripped upper receiver machined from certified 7075-T6 aluminum billet. Built around LanTac&';s patent-pending SMOOTHCAM system, this upper receiver incorporates a specially contoured cam pin recess that works in concert with a domed head, low-friction cam pin to deliver exceptionally smooth bolt carrier group movement. The proprietary bore achieves a roughness average of just 16 micro inches, far superior to the 32-63 micro inch average found on standard bored or milled uppers, dramatically reducing internal friction and wear over time. Barrel nut threads, bore, and barrel extension surfaces are all machined in a single operation to guarantee perfect concentricity and perpendicularity, contributing to a more accurate and consistent platform. Finished with a Type 3 Class 2 Deep Black Hardcoat Anodized coating for outstanding durability and corrosion resistance, the LanTac UAR is the ideal foundation for any high-performance AR-15 build. Product Highlights Precision machined from certified 7075-T6 aluminum billet for superior strength, durability, and dimensional accuracy Patent-pending SMOOTHCAM system featuring a domed head low-friction cam pin and blended cam recess for ultra-smooth bolt carrier group operation Proprietary bore with a 16 micro inch roughness average, significantly smoother than standard uppers rated at 32-63 micro inches or higher Barrel nut threads, bore, and barrel extension surfaces all machined in a single operation ensuring perfect concentricity and perpendicularity Type 3 Hardcoat Anodized, Class 2, Deep Black finish for maximum corrosion resistance and long-term durability Specs Brand: LanTac USA LLC MPN: LA00221 UPC: 820103732659 Material: Certified 7075-T6 Aluminum Billet Finish: Type 3 Hardcoat Anodized, Class 2, Deep Black Bore Roughness Average: 16 micro inches Compatibility: AR-15 Type: Stripped Upper Receiver System: Patent-Pending SMOOTHCAM Disclaimer: We strive to provide accurate and up-to-date product descriptions, specifications, and images; however, errors or omissions may occasionally occur. We are not responsible for any inaccuracies or discrepancies in the content provided. If you notice anything incorrect or unclear, please contact us so we can correct it. When in doubt, we recommend verifying details directly with the product&';s manufacturer.