Keep a close eye on the temperature and humidity with this Ex-Tech Big Digit Hygro-Thermometer with Probe. Probe extends 18”. Accuracy ±4% Relative Humidity and 2° Fahrenheit. Can be bought with Calibration Salt Bottles to make it very accurate. Humidity range from 10 to 99% RH. Temperature Range 14 - 140°F. AAA battery, built-in stand, and mounting bracket included.