5-Methyl-1H-benzotriazole is mainly used in metal (such as silver, copper, lead, nickel, zinc, etc.) rust inhibitor and corrosion inhibitor, widely used in rust oil (grease) products, copper and copper alloy gas phase corrosion inhibitor, lubricating oil additives, circulating water treatment agent, automotive antifreeze. This product can also be used in combination with a variety of scale inhibitors, bactericides and algaecide agents, especially for closed circulation cooling water system corrosion inhibition effect is very good.