These have to be the least accurate things I have ever seen.
The rectangular one is accurate or accurate enough and has been what I used but I noticed files all had cutouts for these round hygrometers…
Well from my 6 pack 1 is within a margin of error to even be useful.
I get they aren’t expensive but seems like a waste of money for this bad.
Best of luck. Seems they are kinda luck of the draw.
They can I guess let you know trend of humidity go up or down but also do note that I noticed the sensor was installed upside down so readings also were pretty delayed from real world adjustments.