3-Pack Mini Hygrometer Thermometer Meter Digital LCD Monitor Indoor Room Round Humidity Temperature Gauge for Humidors Home Greenhouse Babyroom Reptile Incubator， Monitor (Black)

Came with extra set of batteries which was nice. All work and no issues. Reading seem very accurate.

We put these in a freezer to compare them with the mercury thermometers that we had to check them out. All of the thermometers had the same reading except one of the mercury thermometers which was 5 degrees below the rest. I've read that the mercury thermometers are more accurate than the digital or metal spring ones, but all of ours were within 1 degree of the others (except the bad one).The only bad thing about these for me was the size of the temp vs the % humidity digits. I would rather have both readings the same size or have the temp size larger than the humidity reading. However, when I looked at the ad pics, I saw that the humidity readings were larger than the temp readings. So, I suppose I can't dock a star for that.

I have been looking for a hygrometer that will accurately go below 20% RH, this one serves that function, it will measure ok down to about 10% then rail and go no lower -- it seems to be accurate enough, with in 3% RH over the 20-80% range. I have been looking to use it for a simple monitor for 3D filament storage and this will suffice. If you wand to go lower I would suggest SensorPush (however, this is a very pricey solution).

I bought these to monitor the Humidity in my 3D printing Dry Storage for my Filament. So far they arrived pre-loaded with batteries and they have 3 extra unopened batteries as well. That alone was a nice touch.These are perfect for my application and are going to work great. I put one in about 10 minutes prior to writing this review and it's already reading 10% humidity for my dry storage. you can choose between Celcius and Fahrenheit, and the display is easy to read and simple. If you need simple and inexpensive, id go with these!

The three I received work great. They are mostly accurate, only a percentage point or two away from my more expensive humidity gauges. Funny enough, all three of mine give the same readings, which contradicts some of the reviews here. Regardless, I need them to give me a general idea of humidity levels in a space. I'm not conducting scientific experiments lol