Veanic 4-Pack Mini Digital Electronic Temperature Humidity Meters Gauge Indoor Thermometer Hygrometer LCD Display Fahrenheit (℉) for Humidors, Greenhouse, Garden, Cellar, Fridge, Closet

These are super inaccurate.... Bought them for my greenhouse but obviously they are not reliable.

They work but are built very cheap. The screens display glitches and you have to bang or squeeze them till they decide to show anything on the screen. Buy something else

Good value for the cost. I left the 4 in a Boveda 75% calibration package for 24 hours and they were pretty close to bang on, the Calibre IV didn't fare as well. The caliber is adjustable though. The temperature was consistent and in line with a more expensive temp meter. Just note that if exposed to light the meter will heat up, so if expecting a accurate temperature do it in as shielded area.Only critique is the displays can be a bit difficult to read unless looking straight on, looking at a angle and the contrast is difficult

Firstly, I was a bit surprise how consistent these meters were to each other. The first picture was taken after receipting them and letting them stabilize for about 15 minutes. The Humidity readings were all within 2% of each other and the temperature within 7 tenths of a degree. I didn't show the readings against a standard but at ~60% humidity they nearly matched my standard.I would have rated these at 5 stars had I left it at that; but before putting these in their designated guitar case which I am attempting to maintain at 45-55% relative humidity, I waited until the inside humidity in my home dropped a bit. As you can see by the comparison pictures, these meters don't track real well as the relative humidity drops. In fact with inside humidity at 47 - 48% (not shown), these meters still read 5 pts high with none reading less than 52.8%. As I am more concerned with maintaining a proper lower humidity so the wood doesn't dry and crack, vs the high end; I find this deficiency to be significant.Bottom line, given the price point of $14 for 4, though not ideal, as long as long as they do continue to track down somewhat when the humidity drops even further to the low 40's (when the static charge fun starts) I'll continue to use these introducing an error factor.19 Nov Update - downgrading from *** to **. Had an opportunity to compare these meters in a lower humidity environment. I was hoping they would track downward from my earlier comparison points but at 45%, then 44% humidity, the meter still read 50%. See two new additional pics

These seem to work quite well. I opened the package and laid all 4 out next to my existing hydrometer/ thermometer and all 4 were within a degree of temp and a percent humidity of my hydrometer (which I trust). I'm using them in 1L mason jars for curing cannabis. I put 62% boveda packs in the jars and the unit read 63-63% within 24hrs. Does exactly what i need it to do.