Planetwaves PWHPK01 Humidipak Two-Way Humidification System

The Two-Way Humidification System (formerly Humidipak) is the only maintenance free, two-way humidity control system for guitar. It automatically maintains the optimal 45-50% relative humidity level within your instrument case, eliminating the guesswork and potential mess related to refilling a humidifier.
Unlike refillable humidifiers, the Humidipak system provides true two-way purified humidity control by adding and removing moisture on demand. No more manual adjustments based on seasonal changes, geographic locations, temperature, or other factors.
The Humidipak Kit comes with 3 Humidipaks and a soft mesh pouch that will not harm your instrument’s finish. Humidipaks last between 2 and 6 months and should always be kept in a sealed environment like a hard-shell case. Once the Humidipaks become firm, discard and replace using the 3 refills that come in the Planet Waves Humidipak Replacement Pack.
The first two-way humidity control that maintains a constant 45%-50% relative humidity level within your instruments case
Protects your instrument against warping, cracks and other damage cause by lack of humidification
No more manual adjustments based on seasonal changes, geographic locations, temperature, or other factors unlike refillable humidifiers
Eliminates the guesswork and anxiety of maintaining your instruments proper humidity level