KT THERMO Sauna Hygrometer for Sauna Room, Indoor Humidity Monitor, Sauna Accessories for Infrared Steam Saunas

This is a 4″ dial-type hygrometer for relative humidity measurements. The legends are large and clear and easily read. The area below 30% is colored grey, to indicate a too dry condition. It is intended to be hung on the wall of a sauna. There is an calibration screw accessible through the back, although you shouldn’t have to touch this.We have several humidifiers in the house to help with air quality in the winter, and we had no way to measure their effectiveness.I have adapted it for portable use. I made a little stand to allow it to be easily moved from room to room. We placed it in our sunroom and observed a 30% reading. After running the humidifier for several hours the reading went up to 40%, so this seems to work well for our use.I like the metal construction, the passive analog dial, and the fact that it does not need batteries to operate.Minus points:1. The listing says “Use the foldable back stand to position it on a flat surface…” but there is no stand. I made my own.2. The box is labelled “Thermometer” which is incorrect. Apparently the company makes several different instruments but uses one standard box for them all.3. There is a keyhole slot on the back for hanging, although a screw is not included. (A standard drywall screw fits perfectly).I rate this simple instrument 4 stars, discounting one star for the three points mentioned above.