This little device will give you much data. When exported to a spreadsheet where you can amplify that data into a wealth of information about the temperature of the area you are measuring over a period of time. I like that you can adjust the sample points (using your computer).
For me, my best use was with my refrigerators and freezers. Make sure you keep them as cold as recommended without overdoing it and donating your hard earned money to the utilities company.

This has been excellent for both determining the calibration of our home thermostats (which turn out to be as much as 2-3 deg. F off in some cases) and tracking temperatures in areas that experience extremes (e.g. our back sun porch). One minor concern: Once you turn off the recording, you can only reset it to start again by connecting it to a computer. Great price, too. Documentation is a little dicey (some sounds like it was translated, maybe from Chinese.) Didn't use the software it came with; downloaded the current version from their US website.

This little data logger is pretty cool! It is really basic but does a great job. I used it first day to check my fridge, set it up, put in in there, pulled it out the next day and bam, there is the data! A lot of reviews say the software is poor, I disagree, the software is very basic (dowloaded from their website) but it works really reliably. It allows you to very easily export to Excel which was my goal anyway, from there you can slice and dice the data and graph as you please. I guess I would rather have the basic, reliable, software than something complex, after all it's a temperature logger, it's just a bunch of data anyway. Also in regards to support, I did contact them with a question, obviously China based, and they were extremely helpfula nd quick via email. Highly recommended!

Works perfectly. Just need to download the software from the Elitech website and insert the unit into a USB port to get started. Once you have the temp data recorded, the software puts out a very nice Excel export that includes a really nice time/temp graph.

I am using the device to check the performance of my remote Ecobee room sensor (lil'bee). Unfortunately, as I expected, my lil'bee isn't really doing a very good job at controlling the set temperature in it's dedicated room.

One RE-5 con: The software user interface and the instructions are not very well written. It's clear that Elitech didn't pay much to get a clean English translation.

Looking for a good backpacking thermometer? This is it. Weighs nothing, and has a slot to secure it to a pack. The software is a bit wonky and the instructions are clearly a direct translation from Chinese, but understandable if you think about it for a minute. Seems to be pretty accurate, it was always within a degree of two different digital cooking thermometers I have that read to the nearest degree. Reads the current temp when the > button is pushed, and you can cycle thru to see the low/high temps.

The battery cover on mine was in pretty tight, but worked easily once removed--I recommend using a nickel or a quarter, NOT a screwdriver. Remember 'lefty loosey--righty tighty' or counter-clockwise to open. A firm but gentle pressure gets it moving. Be sure the little tabs are in the right place when you try to close it up. Didn't have any problems once it was open the first time. Others have had problems with seals/waterproofness, but all the seals on mine are perfect, and I don't plan on taking it swimming. I use a small piece of tape to secure the USB cover--the friction fit will hold it, but not securely.

So, not perfect, but for the price, pretty close.