ATI AR15 Multiple Caliber Stripped Metal Reinforced Polymer Upper Receiver
ATI AR15 Multiple Caliber Stripped Metal Reinforced Polymer Upper Receiver, Accepts standard mil-spec parts Multi-Caliber: 5.56mm, 300BLK, 22LR, 6.8 SPC and others Material: Polymer w/Insert Patented Metal-reinforced polymer upper receiver Lightweight with durability of a forged aluminum upper Metal insert to reinforce critical areas of the upper Only 1/2 a pound! (7 ounces)