The CarbonX active base layer flame resistant undershirt is the ideal solution for active wearers who want to keep comfortable even in potentially dangerous conditions. It is made from CarbonX tk-60 fabric, a lightweight, double jersey interlock knit comprised of a proprietary blend of high-performance fibers, including hydrophilic fiber designed to absorb and wick away moisture. This Crewneck style undershirt features long sleeves, elastic wrists and is permanently flame resistant.