Blackout Defense .223 Wylde 16 Barrel Mid Length Fixed Gas Block Forward Assist FDE Upper Receiver

Wraithworks Billet Slick Side AR-15 Upper Receiver - Black | No Forward Assist or Brass Deflector

TACFIRE AR-15 Billet Slick Upper Receiver Black

GUNTEC AR15 SLABSIDE STRIPPED BILLET UPPER RECEIVER BLACK

AERO PRECISION M4E1-T 5.56 NATO 11.5" Complete Upper Receiver | Black

BEAR CREEK ARSENAL 300 B/O COMPLETE UPPER 7.5 BRL 1:7 TWIST PISTOL LENGTH GAS MLOK

Sons of Liberty Gun Works SOLGW 14.50" Upper 5.56x45mm M-LOK Rail - Tactical Excellence - M4L89BSCHF14.5

DIAMONDBACK FIREARMS QPQ 223 Wylde 18" Black Stainless Steel Barrel