Our G4 Uppers come standard with a hard anodized black coating (MIL-SPEC MIL-A-8625 Type III).
Upper not compatible with hand guards featuring anti-rotation tabs without modification. *
IMPORTANT!! You MUST use the G4 Enhanced Cam Pin in the G4 Side Charging Uppers!
Use of a Standard Cam Pin will cause the Bolt Carrier Group to lock up in the G4 Upper Receiver and be VERY difficult to remove and could damage the Upper Receiver.
We are so confident that you will be 100% satisfied with this product that we have backed your purchase with our 30 day money back guarantee. Made in USA