PAPR (powered air-purifying respirator) and supplied-air (SAR) hoods and helmets cover the head and face to allow clean air to be directed to the worker. Loose-fitting PAPR hoods do not require fit testing and are often worn by workers with facial hair because they do not need to seal to the face. PAPR helmets have a hard shell that helps distribute headgear weight for improved comfort. They also have a slimmer profile and higher heat tolerances than hoods. Some helmets also have features that allow welding lenses to be added. Belts and harnesses support blowers and batteries.