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

I used it at work and home. Small accurate. Reasonable priced and came with extra batteries.

Love these. So very easy to set up and use. Batteries included. Tells temperature outside and humidity levels inside house. Highly recommend it! Great value for the price. Easy to read and looks nice. Can place it on shelf or stick with adhesive to a wall. Adhesive included.

Maybe a percent off hear and there from device to device , but you get the idea, seems to work well

I got these to keep in a chicken brooder to make sure they are at the right temp. These little things are great.

Muy bueno y preciso

Edit: One of the two now reads 10 degrees higher than the other, initially it was 2 degrees off. Lowered rating as they've only been in use a week.Out of the package these read 2 degrees different and continue to do so. Not sure which is right but in reading review after review on darn near every multipack hydrometer option Amazon offers I believe this is kind of the way it goes. Every pack I looked into had 8-10% 3 star ratings centered around the lack of calibration capabilities and variences between products so I knew it was a possibility. I looked at the options that I could calibrate and the price per unit made it unreasonable for me. Because the varience range is acceptable for me I went with the cheaper option and the fast delivery. I have no trouble reading the display and apprechiate the large number.These came running (no off switch) but they also came with extra batteries. I'd much rather they had some sort of strip to keep the batteries from running, then they could keep the extra batteries and I wouldn't have to feel guilty over the waste and environmental damage.

one of the 3 of these I have will power off when bumped. Otherwise, batteries last a solid year and it's a nice addition for my kids' room with the humidifier and to set on top of the analog humidistat. It's pretty good, and at $5 for 2, I can totally afford to replace the bad one.

As others have stated, the hygrometers were operating out of the box since the seller already stuck the batteries in before shipping it out. They're 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 I'm not afraid that they'll do any damage to the guitar if they come lose from their adhesive on their own (although it'll 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, there's enough surface area to be able to securely adhere the double-sided tape to the top and to the desired surface. It doesn't feel like it'll 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&A's 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. I'm 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 you're moving it from a humid greenhouse to a dry exterior then you'll 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 aren't critically dependent on instant read numbers, then this is a perfectly adequate solution.