Quick view Aero Precision Aero Complete Upper 5.56 20" A2 Blk $518.90 This AR15 Complete Upper is the same upper receiver used in the AERO M16A4 Special Edition Complete Rifle and features a 20" 5.56 Barrel with Pinned FSB, A2 Handguard and A2 Detachable Carry Handle.Features : Upper: Standard M4 Upper... Compare Add to Cart