Luth-AR A1 Assembled AR-15 Upper Receiver - Slick Side

Stern Defense Assembled Upper Receiver, Black

LUTH-AR A1 Upper Receiver 223/5.56mm Aluminum Black Hardcoat Anodize Receiver (UR-01-E3-SA)

LUTH-AR A1 Stripped Upper Receiver 223/5.56mm Aluminum Black Hardcoat Anodize Receiver For M16 (UR-01-M16)

AERO PRECISION M5 308 Win Assembled Upper Receiver | OD Green

AERO PRECISION M5 308 Assembled Upper Receiver | Kodiak Brown Anodized

Luth-AR A2 Rear Sight Kit, Fits A2 Upper Receivers For AR-15 Firarms, Black UR-21K

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