Advanced non-acid, heavy duty formula designed for the worst cases of brake dust! Removes damaging brake and rotor dust from all wheel and rim types, including powder coated wheels. Thick heavy duty formula sprays on as a white foam/gel and sticks to the wheel or rim as it goes to work turning to a deep purple/red color as it cleans. This color indicates that the cleaner is binding to and safely removing the dust without harming the wheel finish.