The N-Ferno 6878 Winter Hard Hat Liner w/ Mouthpiece Kit includes a winter hard hat liner with 3 layers of extreme insulation and a thermal mouthpiece attachment for full-face coverage. The 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. The N-Ferno 6867 Hard Hat Thermal Liner has a 100% polyester quilted outer shell, a mid-layer of foam insulation to provide an additiona