M4 Flat Top Anodized Upper Receiver - Stripped Machined from 7075 T6 forgings, this upper receiver features a mil-std 1913 rail for mounting optics and accessories and has M4 feedramps. Machined from a Mil-Spec 7075 T6 forgingHard Coat Anodized per Mil-A-8625F, Type III M4 Feed ramps Made in the U.S.A These uppers are machined to extremely tight tolerances for a more accurate build. Seating the barrel may take additional force. Light taps with a rubber mallet will do the trick. Add a plain or engraved port door + forward assist kit from the drop down menu. Choose one of our upper engraving graphics from the drop down menu. See reference "CHART A" and "CHART B" tabs above. PORT DOOR GRAPHIC ENGRAVING REFERENCE CHARTTHESE ENGRAVED PORT DOORS COME WITH ALL HARDWARE NEEDED FOR THE PORT DOOR AND FORWARD ASSISTEXAMPLE 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 SKU: UPC: Maximum Purchase: 20 units