Product review (4 stars): accurate enough for consumer use indoors
This is a temperature and humidity digital display which is powered by a single AAA battery (included). The accuracy of any device such as this is tricky because it has to be measured against similar devices which may be inaccurate. I have two other devices which measure temperature and I can say that this seems to measure temperature fluctuations much more rapidly than either of them do. It came within a half degree to a degree and a half of the one that I felt was more accurate.

My general sense is that this is a sensitive and sufficiently accurate device based on its performance in a room which was warm and then cooled with air conditioning as it seemed to make reasonable adjustments  based on how I felt. It also has much finer gradations (to the 10th decimal place). It also responded to the focus of a light which radiated heat when I positioned the light above it and the temperature fluctuated slightly with the added warmth.

In terms of the humidity reading, I have a very high level air cleaner which monitors humidity and this was within 2-4 percentage points of its reading. I think the fluctuation within the room was accounted for by the fact that they were on opposite ends (except for the short time in which I took the photo) the and air cleaner was humidifying the room from its water tank (hence, it read slightly higher). This leads me to believe that the reading on the ThermoPro is pretty accurate for a consumer-level device. It's certainly accurate enough for daily use, but it's not scientific level accuracy (nor did I expect it to be).

In terms of the construction, it's made entirely of plastic, but is not flimsy. It's a mid-range product in terms of look and feel  a simple design with two options for viewing  a little stand on the bottom which flips out and clicks in place or lies flat and a magnet. The main reason I'm giving this 4 stars instead of 5 is that the little stand has only one position so you can only view the display at one angle. Depending on the lighting, this angle may be a very poor option for your viewing. With my desk light on, I could see strong shadows of the digital display that made it nearly impossible to see the readings. It was fine with the lamp off, but the limits on the display angle make me cater the environment to the device. One more notch on the stand for a second angle likely would have solved this. Fortunately, the other option for display, the magnet, is a good one. At a 90-degree angle, this can be viewed well under the lighting conditions I have and the magnet is strong enough to hold the weight of the hygrometer without it sliding down. All in all, for casual indoor consumer use, I think this is accurate and handy for determining temperature and humidity.

Note: I received a free sample of this product for my assessment.