For those who do not know, a hygrometer is a device,measuring air humidity. The gadget displays temperature and humidity at once. In order not to be puzzled about the numbers, it also shows a smiley - smiling means that everything is normal.
Shows the temperature and humidity in the room, remembering this, also has a calendar and an alarm clock. All this is enclosed in a simple and pleasant design, it is powered by one AAA battery.