4 Pack Mini Digital Hygrometer Thermometer Gauge, Indoor Outdoor Temperature Humidity Meter for Greenhouse Humidors Incubators Reptile Terrarium Jars, Fahrenheit (℉) or Celsius(℃) (4)

These work great around my 3D printing shop for monitoring humidity levels. They're cheap enough that I've taken to using them for making sure that humidity levels stay low in the sealed bins and even individual sealed bags I store my 3D filament in. Some have complained about their readings varying a lot, but the 8 I have so far all read within 2-3% of each other.THEY HAVE LONG "MEMORIES" THOUGH. I think this is why people complain about variations with them; it can take them a *long* time to settle down and read accurately if they've been exposed to extremes of humidity, especially on the low side.I've noticed that when I've had one of them in a filament bag with fresh dessicant (reading 10%, the lowest they go, maybe much lower than that), if I take it out and leave it in just room air, it can take days (and days!) for it to read the same as others that have been in the room air all along.If you have a unit that's "dried out" like this, put it in a baggie with a very lightly damp paper towel overnight, then let it sit in room air for a day and you'll probably find that it's agreeing with the others again.The same thing happens but to a lesser extent if they've been exposed to high humidity for a long time as well.If you let them sit long enough, they'll all eventually settle down to pretty close to the same values. I have a total of a dozen of these, bought over a period of more than a year, and they'll all agree with each other within a few percent if I'm just patient enough :-)

I needed to track the humidity in the room and containers of 3D printing filaments and these little meters work great. They roughly match my more expensive weather station indoor reading and are small enough to be included in the container with the filaments. I also have one attached to the printer to monitor the humidity of the reels in the feeder. These work great, are low priced, and are accurate. I highly recommend them!

I like these little fellas work like a champ and they almost agree with each other. If you just need a close enough these will do the trick.I have had them in with my filament dryer and nothing broke. So go get em.

I bought these to put in my Bearded Dragon enclosure so I can monitor the temp and humidity is different areas of the enclosure and also in my Dubia roach colony. The work great they stick very well and were a great value for the price. They even came with extra batteries. So very happy with my purchase and would definitely recommend.

I needed some hygrometers for a 3D filament enclosure that I was making and these came recommended by the designer of the enclosure I'm printing. I accidentally ordered 8 of them (only needed 4), but I'm keeping them because of the great customer service this company provided.While the hygrometers are great, providing both temperature (in C or F) and the humidity, it's the extras they provided that are over the top. I opened the package of 4 and saw that there were 4 batteries, that made sense, so I was prepared to open them up and install the batteries. Much to my surprise they all turned on when opened, so these are SPARE batteries, one for each unit! That's incredible. In addition they provided SIX double-sided tape discs for attaching them to a surface, so they even gave you TWO spares of those! Top notch!

Great price. Low accuracy. Side by side the number varried +/- 5 points. A tad much as 5 is 10% of 50% humidity and 10 (range) is 20% error, so maybe 80% accurate. Perhaps you get what you pay for, or things are just priced at what value they bring, plus markup, plus inflation…

Great product! Simple, compact & very easy to read.

Received as described and they are functioning as they should.