This Copper Based Anti-Seize is the barrel thread compound used and preferred by many professional gunsmiths. The high copper content protects mating parts and provides a shield against high temperatures seizing and galling. C5-A can be used on all steel alloys including all stainless steels, brass, cast iron, copper and all plastics. The 4 oz container includes a brush-top for easy application, and the 1 oz tube is perfect for your range box. Meets Mil-Spec MIL-PRF-907. CANNOT BE SHIPPED OUT OF THE U.S. This item can only ship UPS Ground within the continental United States.