Our metal rust remover spray contains citric acid and sodium gluconate. It can decompose strongly using a special formula, quickly remove metal oxides, provide long-term protection, form a dense protective film, and prevent the re oxidation of stains for a long time. Its usage is very simple: 1. Wear disposable gloves before use. 2. Spray this product on the area that needs rust removal and apply it evenly with a small brush. 3. Wait for 30 seconds, wipe clean, rinse with clean water, and air dry. And it will not harm the metal, cause corrosion or trigger chemical reactions on the metal.