I was nervous reading the reviews but for the price, with the fact that it works with the old method without battery, it's perfect. I bought two, which placed side by side, show the same values. I checked these thermometers with my infrared thermometer that indicates the same thing despite its tolerance to 2%. I did not check what hygrometers for now but there is always the possibility of (dis) hygrometers set by the calibration screw (set to manufacture: it is better not to touch it for nothing). I start with the idea that it was set at best. What is the tolerance of the measure? That's enough to tell me if the room is dry, moderate and moist.
