Review on AikTryee 4-Pack Mini Digital Thermometer Hygrometer: Precise Indoor Humidity & Temperature Monitoring Gauge 🌡️ with LCD Display Fahrenheit (℉) - Ideal for Humidors, Greenhouses, Gardens, Cellars, Closets, and Guitar Cases by Scott Pentapati

If you need accurate readings, look elsewhere. I bought 4 packs. When I opened the package they were all "on" with the batteries in place. So who knows how long they will last and how long these batteries will last. But my biggest complaint is the inaccuracy. Of the 4, 2 were read by 58%, one was read by 52% and the 4th was read by 18%. And the temperature readings were different. There is no way to calibrate. So if you want accuracy, spend your money on a good one.