N Ferno 6876 FR Winter Hard Hat Liner + FR Mouthpiece Kit 2 Layer Size:Kit Hazwik Soc's mold around corners Hazwik Soc's mold around corners and conform to uneven surfaces to prevent and soak up spills and drips Use this tube for detecting Ammonia in the air or in industrial areas and for determining the environmental atmospheric condition The N Ferno 6876 2 Layer FR Winter Hard Hat Liner w Mouthpiece Kit includes a winter hard hat liner with 2 layers of insulation and FR technology to meet ASTM F1506 and also a thermal mouthpiece attachment for full face coverage Both the N Ferno 6882 FR Hard Hat Thermal Liner and N Ferno 6872 FR Thermal Mouthpiece have a fire resistant outer shell and lining made of 60% modacrylic cotton and 40% cotton twill blend to stand up to tough environments and meets requirements of performance specification ASTM F1506