100% Pure Green Cotton masks have a 300 thread count outer fabric barrier that is comfortable, durable, water resistant with an antimicrobial finish that wont wash out. Antimicrobial chemistry prevents harmful micro-organisms, and is EPA certified. 100% Cotton. 2-layer construction for maximum protection. Eliminates odors caused by bacteria, mold, mildew. Ready to use. Washable & reusable Replaces 3515070