CONCENTRATE. A powerful acid-based(hydrofluoric) formula. Professional strength wheel cleaner & brightener to be used on wire wheels, chrome & alloys. Instantly removes road film, & oxidation on metals to restore luster. Will also remove brake dust. Biodegradable. Dilute 1:4 for normal use, 1:2 for brake cleaner removal & 1:1 for severely rusted chrome wheels.