ScentLok Men's Baseslayers Lightweight Long Sleeve Top 100% Polyester Antimicrobial treatment fights odor-causing bacteria while Scent-Lok activated carbon adsorbs a wide-range of odors Underarm gussets for ease-of-movement Activate garment before use in the field. Place in household dryer on high heat for 40 mins; immediately store in an air tight container. For best results store in Scent-Lok lined bag. Repeat process every 30-40 hrs of use. Do not use commercial dryers. MU