Five layers of protection Outer layer : waterproof non-woven fabric Two layers of anti-bacterial melt-blown fabric Hot air cotton layer high loft permeable, elastic, ultra-soft and retains heat Inner Layer - soft, skin-friendly non-woven fabric Filters 2.5 PM, droplets, industrial dust, haze and other fine particles Two elastic ear loops Foldable GB 2626 - 2006 FDA Registration