Koch Chemie Reactive Rust Remover is a powerful, pH-neutral cleaner made with reactive agents and extra high performance detergents. Superficial rust, metal particles, burnt-in brake dust and other non-organic pollutants are swiftly and thoroughly cleaned away. Gentle for materials. Components are harmonised for a longer contact time / moisturisation, so that the reactive agents can dissolve tough stains and burnt-in particles effectively. The cleaner, once it has dissolved the dirt, turns violet in colour. The special surfactants in the formula coat and disperse the partially dissolved dirt, so it is easy to rinse it off.