Black Digital LCD Thermometer Temperature Monitor with External Probe for Fridge Freezer Refrigerator Aquarium (Fahrenheit) (6pcs)

I bought a set of 3 of these, and I wasn't expecting much at this price point. All three are within a few tenths of a degree of each other, and I checked them against more expensive equipment I have. One was so precise that I am now using it as reference for calibrating temperature sensors in my home control systems.If they should fail before expected, or lose accuracy, I will try to remember to come back to update this review.

I have used 5 of these to monitor the inside of electronic racks so that I can see the temperature on the front of the rack. They appear to be reasonably accurate compared to other calibrated temperature devices in the room (in the morning when i arrive and everything was shutdown overnight). I have had no failures, batteries last probably close to a year, but I didn't record any info on that, it wasn't a nuisance at least.

Appears to work. Batteries tend to be near end-of-life leaving one to wonder whether this is why they are so inexpensive.

6/??/21 - My wife and I live on a sailing catamaran in Mexico and our refrigerator and freezer are working overtime in this 100+ degree heat. I needed a way to monitor how they're working and I put one in each section of the refrigerator and freezer. All works very well and I'm saving the 3rd one for another application if I should ever find one.UPDATE 6/21/22 - These do work great but one of my three just went bonkers. It's registering below 0° in my frig when it's actually about 37°F. I even got the LO message a few times. I swapped out batteries to see if that was the issue, but no joy there. I thought maybe it was reading in C instead of F even though F was indicated on the display. I eventually gave up and used my 3rd extra one that I mentioned in my earlier review and that's working fine. But I really have no complaints as these do work perfectly well. I just happened to have one that went bad on me. Not too bad after using the for a year...on the same batteries too :-)

These arrived today and they are quite disappointing on several levels.Others have already mentioned that the -58 degree range is complete fabrication.In a freezer test, two of the thermometers read LO while the 3rd was hovering at 3.9F. A lot of people have said they go "Lo" at -4. If that's the case, then one of the thermometers was off by almost 8 degrees. I suspect that the ones I received were going Lo at 0. Either option is unacceptable in temping a freezer.In a refrigerator test, all three settled around 41 degrees. I had a cooking probe thermometer that I added to the mix. It came in at 37. The refrigerator was set at 34, so I need to do more testing!As they were warming to room temperatures, one of them had as much as a 6 degree temperature differential from the others. Once they all came up to temp, they settle back down to the 2 degree differential. But even when they settled on a temp, all three units were reading 3+ degrees higher than the weather station on my desk, which matches the performance I saw in the refrigerator test.I'm also concerned that the batteries were installed and the thermometers active when I opened the packages. How long have they been reading the temperature in the Amazon warehouse? Do I have 2 years before they go dead? Or 2 weeks?I'm tempted to say that they aren't bad for the price, but if you can't trust a thermometer to be accurate, it's not worth anything.

As much as I love them and had bought so many of them through the years, some of them turned out not reliable. They messure very different temperatures in between for more than 3 degrees difference.

I bought two packages of these to use in my RV. I had them placed strategically around the RV to give me outside and inside temperatures. They are cheap enough and very convenient. Always on display so you don't have to push a button for a reading.

This little probe thermometer works perfect for double checking my egg incubator temp. I needed the probe thin enough to fit through the air vent hole because that way the lid can stay sealed and also would not need the thermometer inside the incubator with the eggs/chickens. I just stick the probe and part of the cord in and leave the rest wrapped up and tape the display screen on the back to the lid of the incubator.