Respiratory masks for prevention of dehydration of airways [non-medical use]; Respiratory masks for wear on faces, providing personal humidifiers; respiratory face masks that humidify airways of the respiratory mask wearer using humidity in the wearers' own breath; Filters for respiratory masks for prevention of dehydration of airways; Respiratory masks for breathing moisturized air during travel, for example airline, train or automobile travel; Filters for respiratory masks for breathing moi...