Bests & Worsts Reviews from Amazon

I purchased two of these as I wanted something digital and I liked that it recorded the highs and lows for each: humidity and temperature. Right out of the package they both read identical humidity and temperature which was great. I then brought them to my work and put them in a stabilty chamber to test against a calibrated expensive humidty guage at 63.3% RH and 25.x C. Both units measured within a single percent of RH and ready 25 C. I then calibrated the units in a nitrogen filled instrument with a calibrated unit. The calibrated unit read 0.0 % RH while both units read 16. I figured out that these units DO NOT work below 20 % RH and instead display 16 %. I then tested them in open rooms compared to a calibrated unit at 20-30% RH and these babies read within a single unit of % RH and about 0.5 degrees C. I have no way of calibrating them higher and not sure how high they will read accurately but I'm curious to see what they'll read outside in the rain. Otherwise they are great units for the price.