The RCBS Formula 1 Walnut Shell Media is a treated cleaning solution designed for reloaders to quickly and effectively clean brass cases. Made from 12/12 sieve walnut shells and treated with special oxides, this 5-pound media removes dirt and debris efficiently, leaving cases ready for reloading. It works seamlessly with the RCBS Sidewinder and most vibratory case tumblers, ensuring consistent results. Proudly made in the United States, this media delivers exceptional cleaning performance for demanding reloading tasks.