Bests & Worsts Reviews from Amazon

So, when I was looking for a hygrometer, I saw several different kinds, many of which had less than stellar reviews (in excess of 20% one star reviews). When I saw this one I thought, well, less than 10% of the reviews were bad. Plus it is relatively cheap (compared to others). So I took the plunge and bought them. Big mistake. They got delivered today and I've had them out of the box for over four hours. The temperatures are accurate (within .2 degrees of each other, and in line with house thermometer), but the relative humidity readings are not working. They all show a value - 48, 52, 54, 56 - but that value hasn't changed since they came out of the box. I put them in a humidor I use to store Cuban cigars, and the digital hygrometer (calibrated with a Boveda calibration pack) has that humidor at 69.8% humidity and 68%F. These four hygrometers have been in that humidor for over three hours and the humidity readings haven't changed since they came out of the box. The temperature is fine and appears accurate, but that isn't why I bought these. So, bottom line is if you are still reading this, you are taking your chances if you buy these hygrometers. Granted there are quite a few satisfied customers. However, you are taking a pretty significant chance that you will be one of the many who get something that doesn't work. Scrolling through the negative reviews it appears that more of them are recent (within the last year) so maybe quality control has been slipping at the factory. I see that the company has posted they have a 30 day guarantee on the product. I'll be back to update this as to my experience trying to return them.