Review on Mini Digital Thermometer Hygrometer 4-Pack for Indoor Humidity Monitoring - Fahrenheit (℉) Temperature Humidity Gauge Meter - Ideal for Humidors, Greenhouses, Gardens, Cellars, Closets, Fridges, and More - by DWEPTU by Jacqueline Garrabrant

I don't have a photo of all 4 together but after some time to get used to the surroundings they all read the same numbers. I have really good ones. However, they were already in the box when I received them. Who knows how long they'll stay on the shelf. Extra batteries were included in the package but they only lasted 3 hydrometer replacements not 4. So you end up having to buy batteries for the 4th. Same goes for double sided tape, it only holds 3, not 4 like you ordered and you can't tape all 4 hydrometers if you want. That's the only reason I gave 4 stars.