The main thing is these hygrometers are small and inexpensive. Just don't expect them to be really accurate. I had differences running from 1% to 5% among the different units. They also take a fair amount of time to adjust to humidity changes, compared to a more expensive model I have (the E-Ink from Govee). The deal breaker for me was the fact they are difficult to read at pretty much any angle except dead-on. I ended up buying the Govee E-ink for that reason (but the Govee is much more expensive).