AERO Precision AR15 M4E1 Enhanced Upper Receiver

Radian Weapons Model 1 10" Upper Receiver and Handguard Set, Flat Dark Earth

GUNTEC AR15 SLABSIDE STRIPPED BILLET UPPER RECEIVER BLACK

Battle Arms Development WH556-URS-ODG Workhorse Upper Receiver Aluminum OD Green Anodized Receiver for AR15/M4

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

AERO PRECISION M4E1 Threaded Complete Upper 16" 5.56 Barrel w/ 15" M-LOK ATLAS R-ONE Handguard - BLK

GUNTEC AR15 STRIPPED BILLET - UPPER RECEIVER BLACK

LBE Unlimited M4 Stripped Upper Receiver, Fits AR15, Black Finish ARSTUP