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. Unlike refillable humidifiers, this 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. Humidipak comes with 3 packets and a soft mesh pouch that will not harm your instrument's finish. These packets last between 2 and 6 months and should always be kept in a sealed environment like a hard-shell case. Once the packets become firm, discard and replace using the 3 refills that come in the Humidipak Replacement Pack (PW-HPRP-03). This all new, reformulated, patented two-way humidification system maintains 45-50% relative humidity which eliminates all maintenance and guesswork. This system is recommended by Taylor guitars and others for maintaining the stability and playability of your instrument. Features

• 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 instrument’s proper humidity level
• No water, no drips, no mess
• Custom made by Boveda for D'Addario

Item shown: Planet Waves Humidpak Automatic Humidity Control System for Guitar Model #: PW-HPK-01 UPC: 019954952907