Product review (5 stars): Just what I needed!
My apartment has its own heat/air conditioning but the heating system does not include humidifying. I have a Vornado humidifier to resolve probable dryness but no way to know accurately what the level was and if it covered the room where the humidifier was not placed.  My thermostat gives me my temperature and this unit agrees with what the thermostat says so I know it is reading accurately.  Now that "humidifier season" is about to begin I can accurately know if the humidity level is healthy.  It's easy to read and the guide at the bottom of the display informs me of levels which are either to high or too low.  My furniture is white and it blends in nicely with it so doesn't "appear noticeable".