D'Addario brings you Boveda's patented technology as part of our instrument care line. 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. **INCLUDES: -1 Headstock pouch -1 soundhole pouch -3 packets -1 instruction sheet 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 instrument’s proper humidity level No water, no drips, no mess Custom made by Boveda for D'Addario