Review on 🌡️ Rojuna Mini Thermometer Hygrometer 5-Pack: Large Number Fahrenheit LCD Display for Humidors, Greenhouses, and More by Ben Duncan

It is not possible to test the validity or accuracy of these small hygrometers with a newly calibrated instrument but I will say that after being left in static conditions for 1 hour they all within +/- 1 in relation to temperature and humidity. If they're wrong, then at least they're wrong all the time, which seems good to me, and they should work fine, at least for now. And if not, they were cheap enough that replacing them wasn't much of a problem.