6 Pack Mini Hygrometer Indoor Humidity Meter, Small Digital Thermometer Humidity Gauge Meter, Indoor Thermometer Hygrometer Monitor Fahrenheit (℉) for Thermostat Reptile Tank, Mason Jars

These mini hygrometers have become indispensable in my filament storage routine. I use them inside my dry boxes / storage bins to keep filament moisture-free, and they do the job well—no surprises or moisture-related prints going bad. The display is easy to read at a glance, showing both humidity and temperature clearly. Their small, versatile form factor means I can tuck one into any container or spool box without taking up space. Considering you get six units in a pack, it’s a great price for what you get. Bottom line: For the price and utility, this 6-pack is a smart buy for anyone serious about controlling moisture in their 3D printing materials.

These little hygrometers work surprisingly well. They read humidity and temperature fast, the screens are clear, and you can stick them in a reptile tank, a mason jar, or a filament bin without any fuss. They are small enough that you will lose at least one within a week, but that is part of the charm. And like most people calling their digital videos films, these hygrometers pretend to be tiny weather stations when they are really just sensors. At least they admit it. No chemistry, no emulsion, no reels, no lab processing. Just data. Which means these hygrometers are already more honest about what they are than half the internet. Good little gadgets. Straight shooters. Not films.

​If you need a cost-effective way to monitor multiple storage containers at once, these mini hygrometer thermometers are a great choice. I bought a pack of these to track the conditions inside my large mason jars for cat food and my vacuum-sealed 3D filament bags. ​Generally Reliable Performance ​While these aren't laboratory-grade instruments, they are generally okay for everyday use. You might notice that each unit gives a slightly different number when placed side-by-side, but they perform consistently enough to tell you if your storage is "safe" or "wet." For the price, they are much better value than the expensive single units. ​Best Uses: ​Cat Food Storage: Perfect for dropping into a large jar to ensure no moisture is getting in that could spoil the food. ​3D Filament: Essential for checking if your desiccant is still working. Even if the accuracy varies by a few percent, it’s easy to see when the humidity starts to climb. ​Compact Size: They fit easily into almost any container without taking up valuable space. ​Final Verdict ​They are priced better than most options on the market. If you don't mind a bit of variation in the numbers, these are an excellent, affordable tool for any "Maker" or pet owner looking to protect their supplies. ​A Quick Tip for your Review: ​Users often appreciate knowing that these typically bottom out at 10% humidity. If you see yours reading "10%" in your filament bags, that usually means it's actually even lower than that, which is great news for your plastic!

The meters seems pretty consistent - after a while, having them closer together, they readings got more similar (photo with blue background was first test. Then, days later, the white background). Very content with the quality for the cost.

These work flawless. I have one in each room and what a difference between rooms on the temperature. The reason I purchased these is so I could see the difference between rooms. These have shown me what room is dryer and where I should also place a humidifier.

They look great and seem to be doing exactly what they're supposed to. Only a slight variance in degree. And humidity readings. Will work great for my 3D printer filament storage.

These are great mini hygrometers/thermometers. They are within 2% humidity of each other and 0.2 deg. F of each other. One of the units was faulty. I used new batteries in the unit, but it only displayed the temperature. The humidity did not display. This is the second order of this item. The first order all units worked perfectly. That's the only reason I'm giving this a 3-star rating because of the failure of one unit. All in all, it's still a great buy... I recommend this product even though I had one failure out of six.

These work great! I will say the way they are they only do Fahrenheit, but popping them open you’ll find a spot on the board to convert them. It helps to have a soldering iron but you can also just scrap away the solder between the two points. Just look for the blob of solder with a F/C next to it. Worked like a charm. I’m using these in a 3D printer to monitor with the camera. Just easier since everything is referenced in Celsius.