IOSSO Case Polish Cleans and polishes brass casings to a high luster. It removes powder fouling, residue, oxidation, tarnish, and discoloration. Add Iosso Case Polish to your media before tumbling. It works with the media to reduce tumbling time and gives your brass a like-new finish. Shines to a high luster and protects from future oxidation. Use Iosso Case Polish on soiled casings or on casings that have been pre-cleaned with the Iosso Case Cleaner. New Bio-Based Formula, safe to the user and safe for the environment.