Tough-PAC PDA is a hard shell case for iPod touch 5th, 6th or 7th generation. Biomaster® silver ion technology is incorporated during manufacture. This inhibits growth of contaminating bacteria and fungi by more than 99.6% for the life of the product. It's not a coating, it's permanent. The only medical grade case system for iPod Touch Tested to ISO22196 international antimicrobial standard.