I bought this to read humidity in my basement and initially loved the product. I calibrated it and it was accurate-awesome. Seemed to remain accurate for 3 weeks, then one day it decided to get stuck at 50%, 50 degrees and wouldn't change regardless of where I put it. Reset it, then it only read 90% humidity. I think mine was a fluke though, judging by the other reviews. Thankfully Amazon refunded my money so no harm done.