About the D'Addario PW-HPCP-03 Replacment Humidpak for Two-Way Humidity System:
 
Ensuring that your instrument and case are properly humidified before using the Humidipak Maintain System is essential in order to receive the maximum benefits and longevity of the product. The D'Addario Humidipak Restore Kit allows you to safely restore an instrument and case that is in a known dry condition or has previously not been humidified to the proper humidity level without any danger of over humidification.