A blend of Hydrochloric and phosphoric acids.For use on alloy and painted wheels,will remove all brake dust,surface corrosion,day to day grime and tarnishing with a little effort,water washable biodegradable.Economical in use and leaves a good bright finish. This is a strong product please test first as you might want to dilute it down! can be diluted with water 5-1. Wear gloves to protect your handie pandies.