The NBS Slick Side Billet Upper Receiver is constructed from 6061-T6 aluminum with a hardcoat anodized black finish. This upper receiver features a slick side profile with no dust door. An anti-rotation cutout is also a noted feature of this upper receiver. This upper receiver is manufactured in the USA. Key Features 6061-T6 billet aluminum construction Hardcoat anodized black finish Slick side profile No dust door Anti-rotation cutout Manufactured in the USA Perfect For AR-15 builders sourcing a slick side billet upper receiver Custom AR-15 builds requiring a clean profile upper receiver without an ejection port or dust door Builders seeking a USA-manufactured 6061-T6 billet upper receiver 6061-T6 Billet Construction and Finish The NBS Slick Side Upper Receiver is constructed from 6061-T6 billet aluminum. A hardcoat anodized black finish is applied to this upper receiver. Both the material and finish are distinct and separately identified attributes of this upper receiver. Slick Side Profile and Anti-Rotation Cutout This upper receiver features a slick side profile, meaning it does not include an ejection port or dust door. An anti-rotation cutout is a specified structural feature of this upper receiver. These are distinct and separately identified design attributes of the NBS Slick Side Billet Upper Receiver. USA Manufacture and Compatibility This upper receiver is manufactured in the USA and is compatible with standard AR-15 components. The black hardcoat anodized finish provides compatibility with a wide range of AR-15 lower receiver configurations. It is a single-component inclusion with no additional components in this listing.