Odin Works 6mm ARC Complete Upper Receiver 21" XL Rifle Length Barrel - 17.5" O2 Lite M-LOK Rail

BEAR CREEK ARSENAL 5.56 NATO COMPLETE UPPER 10. BRL 1:7 TWIST CARBINE LENGTH GAS MLOK

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

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

Odin Works ULTRAlite AR-15 16.1 Intermediate-Length Gas 6.5 Grendel 1:8 Stainless Steel Barrel with Tunable Gas Block And BCG

CMMG Banshee Mk4 AR-15 Upper Group .338 ARC 10.5" Barrel Black

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

BALLISTIC ADVANTAGE Premium Series 6MM ARC 16", 5/8x24, 1:7 Mid Length Gas Barrel for AR10