The N-Ferno 6872 Thermal FR Mouthpiece has two layers of insulation with a modacrylic\/cotton blend shell and liner to provide comfort, warmth and face protection in extremely cold weather work conditions. This thermal winter face mask is made to fit most N-Ferno Winter Liners (sold separately) to double up the warmth on those frigid jobsites. Flame-resistant rated materials meet ASTM F1506 and are classified to CAT 2 according to NFPA 70E. The shell design prevents the mask from being sucked into the mouth for plenty of breathing space and protection from the cold air. The detachable face mask allows you to let in air or remove for speaking when needed. The adjustable hook and loop closure have a secure and adjustable fit to prevent the mask from moving around during any task. Great cold weather work gear for people who spend extended periods of time in cold environments and need such as construction, freight, drilling or mining, delivery service, landscaping, and warehousing.