Our multi-functional metal anti-rust cleaner for car exhaust pipes (120ml set) contains citric acid and sodium gluconate. It can restore luster, will not damage the exhaust pipe and is easy to use. Its usage method is very simple: Please put on rubber gloves before use, then evenly spray the cleaning agent on the exhaust pipe (make sure the exhaust pipe cools to room temperature), wait for 30 seconds, wipe back and forth with a cloth, then rinse with plenty of water after cleaning, and finally dry with a dry towel. And it can remain clean for a long time.