Taylor 80358 ExTech Big Digit Hygrometer
Monitor the relative humidity in your home, office or wherever you store your guitar to protect it against the adverse effects of high or low levels. Easy-to-read display shows temperature and humidity simultaneously. Use freestanding on a flat surface or easily mount on a wall. Comes with built-in tilt stand, wall mounting bracket and 1.5V AAA battery.
Note: 45-55% relative humidity is optimal for your guitar. To maintain proper levels, you may need to use a guitar humidifier.