The Heat-Out Cool'R base layers are made to keep you cool when the heat rises. This base layer is designed to be worn underneath your gear and provide advanced heat management. The stretch fabric will soak up your sweat while the antimicrobial liner will keep it smelling fresh. Built to be lightweight, this incredibly fabric can stretch in all directions yet feel like another layer of skin.; Hi-Tech Fabric blend wicks perspiration Anti-bacterial technology reduces odor Multi-directional stretch