Heavy Duty Wheel Cleaner features a balanced, eco-friendly formula that is safe and effective on all wheels: chromed, polished, powder coated, aluminum, or steel. This highly-concentrated formula clings to the surface of the wheel, penetrating and loosening brake dust, grit, and road grime. It's environmentally friendly and safe! Heavy Duty Wheel Cleaner turns a deep purple so you can see it working right before your eyes! Gentle agitation is all it needs to rid your wheels of stubborn, caked-on contaminants. Steer clear of any wheel cleaner that boasts spray-on, spray-off (with no agitation)... These products are caustic, and a danger to you and our planet. Griot's Garage Heavy Duty Wheel Cleaner now boasts a more pleasant fragrance and is the safe, effective, biodegradable choice!