The N-Ferno 6867 Winter Hard Hat Liner has 3 layers of insulation with a quilted polyester shell, a foam mid-layer and a thermal polyester fleece lining. This lightweight thermal liner is shoulder-length to keep head, ears and neck covered and fits comfortably under helmets or hard hats without feeling too bulky. There are four hook & loop straps on the exterior of the liner designed to securely attach to the interior of a hard hat for versatile protection in extreme work environments. This hard hat winter liner has an elastic strip in the forehead area to keep the liner snug against the face to trap body heat in and keep cold out. Small pockets by the ears are designed to hold regular-sized hand warmers (sold separately). Great cold weather work gear for people who spend extended periods of time in cold environments and need to wear head protection such as construction, freight, drilling or mining, delivery service, landscaping, and warehousing.