Product review (1 stars): This worked great for about 1-week
This worked great for about 1-week.  I put it in a cigar box with a 72% Boveda and I consistently got readings of 72% on the hygrometer.  Now it always reads 54-56% even if I put it in a small plastic bag with a sopping wet paper towel. The temperature gauge still works fine, so it's not like the unit is "broken."  It just doesn't work well.  I took the batteries out and reinstalled, I tried different environments, etc.  No effect.  Don't waste your money.