Review on 🌡️ 12-Pack Mini Digital Electronic Temperature Humidity Meters Gauge - Indoor Thermometer Hygrometer with LCD Display in Fahrenheit (℉) for Humidors, Greenhouse, Garden, Cellar, Fridge, Closet - Multicolored by Kathy Miller

So out of 126 readings were the same and the other 6 were +/- one point off. when I received them the batteries were already in the devices and there was no battery tab on the devices. To recap, the devices have been on since someone put batteries in them and how long they've been in Amazon's warehouse. etc so I don't know how long they will last before I have to replace the batteries.