Hornady One Shot case tumbling media was engineered as an abrasive media to remove tarnish and other residues from cartridge cases before reloading. Dirt and grime that is left on cartridge cases can prematurely wear out reloading equipment so it is a great practice to ensure brass is cleaned before reloading. This corn cob media is untreated and will remove dirt and grime from cases with ease. To improve the case cleaning process reloaders can treat the media with a brass polish to help achieve a mirror like shine. Made In United States of Americawarning-icon WARNING: This product can expose you to Lead, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to - www.P65Warnings.ca.gov.