Bests & Worsts Reviews from Amazon

We eventually bought three, compared them, and found they didn't match. Two were close, 2-points difference, but the third was over by 18-points. Then I found out about the Boveda 32% Low-RH One-Step Hygrometer Calibration Kits sold here on Amazon and bought one. We tested all three. The two that were close were off by +4 & +6 points and the other was just garbage, for which Amazon refunded our money. We kept the others marking the difference on them. IIRC, AcuRite claims +/-2% on the humidity, none of ours hit that tolerance. I know they're inexpensive nonetheless they should work as claimed.