The Antimicrobial version is treated with AEGIS Microbe Shield technology, which is engineered to resist the contamination and growth of bacteria, fungi, and many other microorganisms. The result is a towel that is cleaner and freer from bacterial contamination before and after use. AEGIS Microbe Shield technology is effective against any single-celled organism. They are quite possibly the cleanest things you will touch all day. Washable and reusable.