Aero Precision AR15 Assembled Upper Receiver Anodized Black. Forged from 7075-T6 aluminum this assembled upper is precision machined to mil- spec M16/M4 specifications and features M4 feedramps. Match this upper with one of our AR15 lower receivers for a solid and dependable fit Specifications for Aero Precision AR-15 Assembled Upper Receiver: Manufacturer: Aero Precision Caliber: 5.56x45mm NATO Gun Make: AR Platform Gun Model: AR-15 Country of Origin: USA Features of Aero Precision AR-15 Assembled Upper Receiver M4 Feedramps .250 takedown pin holes Package Contents: Aero Precision AR-15 Assembled Upper Receiver The Aero Precision AR15 Assembled Upper Receiver is a quality addition to the Aero Precision lineup. For more great deals on AR15 Upper Parts by Aero Precision please browse our Aero Precision Gun Parts page. What firearm models does the manufacturer say Aero Precision AR-15 Assembled Upper Receiver is compatible with? The manufacturer says that Aero Precision AR-15 Assembled Upper Receiver is compatible with AR-15Aero Precision APAR501603AC: AR15 Assembled Upper Receiver Anodized Black