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.
Just bought them after the realization of this. I will try to make sure I let you know as I found a really good deal that I’d be happy to share as well if they are good as long as you are fine with used.