AR15-A3 Stripped Upper Receiver, Mil-Spec, 7075 T6 aluminum, W / Hard Black Anodized FinishFeatures M4 Feed Ramps, and a Hard Anodized Black Finish - Perfect to match with any of our Lower Receivers. A3 style Flat Top for Sight or Optic Mounting. Can be used for Multiple Calibers on the AR15 Platform. These receivers are meticulously bead blasted before anodizing and have one of the smoothest most flawless finishes I have ever seen.