Product review (4 stars): I wouldn't expect scientific accuracy out of something like this but these are more than sufficient for most ...
Both of these seem to work very well. I compared them up against the thermostat in my house and the indoor outdoor thermostat and humidity Gage and they were all within 1 degree or 1% of each other. I wouldn't expect scientific accuracy out of something like this but these are more than sufficient for  most average needs. My one big complaint is that the clip/magnet/stand on the back is very cheaply made and one has already broken off.