Original Barrel Nut for the Vltor VIS Upper Receiver Assemlies.
While the VIS uses standard AR15 barrels, this nut must be used for installation in the VIS platform.
CALIFORNIA PROPOSITION 65 WARNING: This product can expose you to chemical(s) known to the State of California to cause cancer, birth defects or other reproductive harm. For more information, go to www.P65Warnings.ca.gov/product