4 Pack Mini Digital Hygrometer Gauge Indoor Thermometer, LCD Monitor Temperature Outdoor Humidity Meter for Greenhouse Jars Incubators Guitar Case, Fahrenheit (℉) or Celsius(℃)

Compared with 2 other more accurate hydrometer and they were maybe 1-3% variation max. Usually closer to 1%. Pretty accurate for cost. If these continue to work well, I have a product I am using them for. I may order in bulk.

I use these to monitor the humidity in my 3D printer room. It's important to keep low humidity for the filament.

Sitting right next to a calibrated hygrometer, these are sort of accurate but fluctuate wildly. So far they will read anywhere from 3 degrees below to 3 degrees above the calibrated one. The messed up thing is they change frequently (the room isn't though!). So all I can say is that you can always guess you are within 6% of the actual number (since you won't know if it's high or low). I sent them back.

Great product.

These little things are great! They are small enough to not get in the way of anything and small enough to stick anywhere, the fridge, a doorframe, the edge of a computer screen, anywhere you can think. It’s nice to see the temperature anytime now and the display is simple to read. I have several of these in different rooms.

Bought these because clearly we have different rooms that seem to be almost 10 degrees off from the other rooms. And was trying to troubleshoot what we could do to improve our energy costs. Was even surprised that there is a two degree difference from our thermostat and the rooms adjacent to it and the hallway where it’s located. Definitely worth the money if your trying to reduce your cooling costs in hot Vegas climate.

Liked all work great

I had them sealed in a bag with a Boveda pack and they all had different reading with a +- of 5% rh

Muy precisos y vienen con baterías nuevas. Funcionan muy bien y son sumamente confiables.