Upper Parts Aviator Arms X-1 Bi-Axial Recoil Device$395.009mm Upper Receiver$115.00Radian Raptor-LT AR10$84.95Radian Raptor-LT 5.56$69.95Radian Raptor-SD 5.56$119.95Spike’s .308 Shim Kit$11.95ST .308 Low Profile Gas Block$29.95M4 Flat Top Upper$115.00M4 No Provision Upper$89.00Delta Ring Assembly w/Mil-Spec Barrel Nut$18.95Billet Upper – Gen II – Mil-Spec Barrel Nut$270.00PRI Combat Latch$19.95Charging Handle – Forged$25.00Charging Handle – .308$28.00Melonited Gas Tube$16.00O-Ring -Anti Rattle$1.50Gas Block Extension$21.00SAR Rail Shim$0.30Forward Assist Assembly Kit$12.00Ejection Port Door – 9MM$7.95Ejection Port Door – .308$9.95Ejection Door Installation Kit$3.50Ejection Port Door$9.95Spike’s Barrel Nut Shim Kit (Set of 8)$11.95ST Low Profile Gas Block$29.95Adjustable Low Pro Gas Block$109.95