Frankford Arsenal Treated Corn Cob Brass Cleaning Media has been designed to quickly and efficiently remove dirt, grit and powder residue from brass cases before reloading to keep reloading dies in top working condition. Media can be used repeatedly, but should be replaced periodically for optimum performance. Sieve Size: 16/20 Sieve SizeTreated: Yes with Frankford Arsenal Ammonia Free Brass Polish