Refills available in a 3-packThe Humidipak system in actionHumidity ControlThe Planet Waves Humidipak system is a patented "two-way" humidification system that can add or reduce humidity within an instrument and its case. This eliminates the guesswork and maintenance commonly associated with other humidification products.It's All RelativeThe Humidipak system lets a musician store their instrument and feel confident that it will be kept at a constant level of relative humidity. The 45%-50% relative humidity level that the Humidipak resides at is ideal for protecting and preserving the finish and wood of an instrument.Safe and SoundFrom your beginner instrument all the way up to your prized high-end acoustic, all instruments are susceptible to warping, cracking, and other damage. By resting in the soundhole and at the headstock of your instrument the Humidipak system helps you avoid these issues, and other problems that can cause expensive repairs.Humidipak Features3 replacement packs for the Planet Waves Humidipak systemAutomatic humidity control protects your instrument against warping, cracks and other damage caused by lack of humidificationNo more manual adjustments based on seasonal changes, geographic location, temperature, or other factors, unlike refillable humidifiersEliminates the guesswork and anxiety of maintaining your instrument's proper humidity level