Mine work somewhat okayish, which is within the margin of error I need them for. I think there was one that was terrible though.

Mostly I use them for the temperature aspect, mostly for reminding me if it’s too hot or cold in my room (because due to my autism, I often don’t notice whether I’m at a comfortable temperature). I have a few scattered about my room and basically they act as a visual prompt to consciously ask myself if I’m at a comfortable temperature, and to act as a rough backup to whatever I’m feeling (because even when I’m consciously aware that my temperature is feeling Bad, I can’t reliably tell whether I’m too hot or cold, so these terrible thermometers at least help me answer “should I get a blanket, or open a window?”