It's important to know the humidity in and around your piano. This humidity gauge is easy to use , portable, self-standing or wall mountable.

Item #S-HT-DDM - This Hygrometer provides simultaneous display of indoor temperature and humidity.
Operates continuously, with expected battery life of over a year.
Temperature range is 14º to 140º and can also be set to Celsius.
Humidity range: 20% to 99% RH
Temp. accuracy: ±1.8ºF (±1ºC)
Humidity accuracy: ±5%
Resolution: 0.1º, 1%
Dimensions: 4” x 2.5” x 0.5”
Length (in): 4
Width (in): 2.5

The memory function recalls and displays the maximum & minimum temperature and relative humidity since the last time the reset button was depressed. Uses 1 'AAA' Battery