The Hygro Thermometer monitors the relative humidity in your home, office or wherever you store your guitar to protect it from the effects of high or low moisture levels. The easy-to-read display shows temperature and humidity simultaneously and can be used freestanding on a flat surface or mounted on a wall. The Taylor hygrometer comes with built-in tilt stand, wall mounting bracket and 1.5V AAA battery. One button display of MIN/MAX readings. Switchable between C or F. RH range: 10 to 99% (accuracy: +/- 5%). Temperature range: 14 to 140 degrees F (-10 to 60 C). Note: 45-55% relative humidity is optimal for your guitar. To maintain proper levels, you may need to use a guitar humidifier.