Optimum Ferrex Remover can be used to remove ferrous oxides from wheels and painted surfaces quickly and effectively. It's simple spray on wash off formula removes ferrous oxides and will also remove tar and other contaminants as well. This remover is a great finishing step to any detailing clay process. While your clay will remove most contaminants on your paints surface, Ferrex will ensure any bonded oxides tar or residues left are eliminated and can quickly be washed off after use.