Mini Hygrometer Thermometer 2PCS Mini Digital Humidity Gauge, AikTryee Hygrometer Indoor Humidity Monitor, Temperature Humidity Gauge Meter for Humidors, Greenhouse, Garden, Cellar, Closet, Etc

I bought 2 of the mini hygrometers and they are giving the same readout that I’m getting from my larger, costlier devices. The size is perfect for placement into mason jars. The additional included batteries were a nice bonus too! There are what appears to be clips on the side that I am unsure of how to use, but am happy with placing them either with the included double sided adhesive stickers, or simply standing/laying down.

I have both of these units stilling side by side in my office and they are 2-3% different. They came with double back tape so you can mount them somewhere, but the battery compartment is on the back, so if you mount these, you will have to tear them off the wall to change the batteries. Not bad for the price, as long as you do not need very precise reading.

I grow plants in a tent, and have to check the humidity levels. These are a great value, but they dont last very long. One lasts, about the time of each grow to harvest, so I have to buy a new pair, about once per year, if I do two harvests per year, but these dont cost very much, so I think thats fine The downside is the adhesive tape, barely stays on, so be careful where you put it, or use another adhesive. it also makes it near impossible to change the battery, but these dont last long, so that isnt much of an issue The display is really easy to read, and its very accurate. Thats why I dont mind replacing them every year. These are cheap, but the value of accuracy, is paramount when growing things in a tent

As others have stated, the hygrometers were operating out of the box since the seller already stuck the batteries in before shipping it out. Theyre small, light, and have a clear and easy-to-read LCD screen. I bought them to monitor humidity in my guitar cases, so their size and lightness are perfect for fitting into the little available space around the guitar and Im not afraid that theyll do any damage to the guitar if they come lose from their adhesive on their own (although itll be a different story if its from something like the guitar case being jostled around). They also come with double sided 3M tape strips and a new set of batteries per unit which makes this a very good deal. Also as noted by another reviewer, almost the entire back side of the unit is occupied by the battery door which means ideal places for mounting are limited to the narrower sides. While this made mounting a bit more finicky, theres enough surface area to be able to securely adhere the double-sided tape to the top and to the desired surface. It doesnt feel like itll come off unless I really pull on it. Out of the box, there was about a 1-2% humidity difference between the two units I purchased and temperatures were about .5-1 degree off. I reset them as specified by the seller in the Q&As by removing the batteries and leaving them out for about 10 minutes before putting them back in. After the reset, the difference in numbers was the same, but after about 5 minutes of acclimating and letting them sit side-by-side on their own, they matched each other exactly. Im assuming that the initial number differences may be due to very sensitive sensors that are reacting to the heat/moisture of your fingers after handling. I also think that the units do take a few seconds to register any changes in humidity/temperature, but that works perfectly fine for my purposes. For example, if youre moving it from a humid greenhouse to a dry exterior then youll probably have to wait a few minutes for the numbers to gradually ramp up/down. If you want more responsive hygrometers you may need to look elsewhere, but if your monitoring situations arent critically dependent on instant read numbers, then this is a perfectly adequate solution.

These are tiny yet I’m still able to read them. I love them. I use them in my leopard geckos tank. I haven’t used the adhesive to put it up on the tank. I just stuck them inside on my hot and cool side. Works awesome. Same temps as what my heat gun is saying. Love that there was extra batteries in the package too!!

I bought the Travel Humidor Plastic Pouches as well. I put one Hydrometer inside the Pouches and sealed it and the other one ( because I bought the Two Pack ) outside on my desk. The one on inside is working nicely and the one outside of the Pouch is measuring the Humidity exactly as my expensive Humidity/ Barometer that I have on my desk as well. Nice Little Unit.

Works as described. Mine were about 5 degrees off on temperature and humidity. Battery life was meh at about 6 months of 24/7 operation. Decent product for the price. Simple to use and easy to read display.

TLDR; don’t expect pinpoint accuracy, but it’s reliable for general readings. Good purchase for its price point. I have no need for scientific measurements; I just need to make sure the air is wet enough for my plants without spending an unreasonable amount. If you buy a pack of two, you notice the two will show different readings for both humidity and temp, and there’s not really a way to calibrate these. However, the readings are still within 1 or 2 degrees of each other. And from testing by transitioning from normal room humidity to the inside of my tropical plant enclosure, it’s definitely able to pick up the changes in humidity within a minute or so. Another note: leaving these in 90%+ humidity for a long time (maybe 6hr+?) will cause the display to glitch out and become unreadable. Moving the device back to lower humidity will fix it if you wait a bit. And if not, just remove the batteries and put ‘em back. That usually fixes everything.

this works great

These little things have been running inside my 3D printing filament boxes to help me check if the desiccant inside is still good. They come in a pair and I only bought one pair to start, then two more after finding that they worked for my application. They come WITH batteries already inside AND replacements which is VERY helpful. I cant attest to their accuracy since I dont have a calibrated hydrometer to check them, but they seem accurate enough. My oldest pair have been running nonstop from 1 October 2020 to now 18 February 2021. I do not know when they will run out.