ski mask

A balaclava, also known as a balaclava helmet or ski mask, is a form of cloth headgear designed to expose only part of the face. Depending on style and how it is worn, only the eyes, mouth and nose, or just the front of the face are unprotected. Versions with a full face opening may be rolled into a hat to cover the crown of the head or folded down as a collar around the neck.