Gyeon Iron will help you remove ferrous deposits such as brake dust and rail dust safe and easy! This unique formula is strong enough to remove this tough contamination, yet gentle and pH neutral. This means Gyeon Iron will make quick work of caked-on brake and rail dust, while being safe to apply on your paint, wheels, trim, glass, etc. To apply, start with a cool wet surface and simply spray this product onto the desired area, letting it dwell. After about 60 seconds you will see the formula change to a deep purple. This illustrates that the formula is reacting and removing the deposits that are on the surface or embedded in the finish! Follow up with a rinse and you are all set. What you will be left with is a clean surface, free of iron and brake dust! Remember to never let the product dry on the surface and to thoroughly rinse or wash off once finished. For any heavily soiled areas, we recommend multiple applications and/or agitating with your favorite detailing brush. Grab yourself a bottle of the Gyeon Iron, brake dust won't thank you, but your car certainly will!