Phase 5 Tactical A3 Flat Top Upper Receiver. Mil-spec type III hard coat anodized finish. Precision machined to M16/M4 specs. M4 feed ramps. Includes forward assist assembly and ejection port cover assembly. Overall length: 8.25 inches. made in specialized factories. Specifications for Phase 5 Tactical A3 Flat Top Upper Receiver A3-UPPER: Mfg Item Num: A3-UPPER Type: ACCESSORIES - GUN ACCESSORIES - UPPER RECEIVERS Master Model Header: A3 Flat Top Upper Receiver The Phase 5 Tactical A3 Flat Top Upper Receiver A3-UPPER is a quality addition to the Phase 5 Weapon Systems Inc lineup. For more great deals on AR15 Upper Receivers by Phase 5 Weapon Systems Inc please browse our Phase 5 Tactical Gun Parts page.