This headcover’s patented thermal exchange device captures heat and water vapor from every breath you exhale and uses this energy to warm and humidify the next incoming breath. And it does this without creating unwanted condensation or freeze up. This thermal exchange keeps your core temperature warmer and keeps your head, hands and feet warmer by eliminating up to 40% of heat loss. Hunt or enjoy other outdoor activities longer by keeping more comfortable in cold conditions. Field-tested in the extreme conditions of Antarctica and on the Iditarod Trail Dog Sled Race in Alaska. Headcover covers nose, ears, mouth, neck and head. Flexibility allows you to pull the mask under your chin, to blow a call. One size fits most. Camo pattern:Realtree AP™.