Protect your acoustic guitar from damaging environmental changes with the D'Addario Acoustic Guitar Soundhole Humidifier, combining controlled soundhole humidification with precise digital monitoring in one complete care system. The sponge-style humidifier suspends safely between the strings without touching the instrument's body, gradually releasing moisture into the guitar to help maintain proper humidity levels. The included digital sensor monitors relative humidity from under 20% to 99% and temperature from –32 degrees F to 122 degrees F, with readings available in Fahrenheit or Celsius. A memory function records recent high and low temperature and humidity levels along with the date and time, giving players a clearer picture of the conditions their instrument has experienced. Together with the built-in clock and calendar, the Soundhole Humidifier makes it easy to monitor and maintain a healthier environment for your acoustic guitar.