They're certainly better then nothing! We all know these type of cheap thermometer/hygrometer units aren't ~exactly~ accurate, but I’ve used them in the past and they're usually accurate enough for say the average reptile enclosure ambient readings. I ordered four of them, and they are just not as accurate as the older Zoo Med versions that I already have. Looking at the four that I just bought, there is a >10% difference across the hygrometers, and a 5-6 degree difference across the thermometers. A deal breaker IMO. I will not buy these gauges again, and I suggest that you don't either.