The Planet Waves Acoustic Guitar Humidifier with Humidity and Temperature sensor is a moisture reservoir that you suspend inside the body to slowly release moisture. The humidifier protects your guitar from damage even in the driest conditions. The high absorption sponge doesn't shrink or deform, avoiding leakage. The Planet Waves humidifier's removable top and removable sponge make it easy to keep the sponge moist. The unit registers temperature and humidity levels from 20%-99%. A memory function records the date and time of the highest and lowest temperature and humidity levels. The Planet Waves Acoustic Guitar Humidifier suspends from strings so it doesn't actually touch the guitar.