Boveda Humidity Control Pack 4 Pack MB49HA-70-4P Dual-Path High Absorption Absorption Humidity Control,

This dual-path humidity control pack absorbs or releases moisture to maintain desired levels. Extend the life of your valuable acoustic instrument with Boveda's 2-way humidity control set. Fluctuating humidity levels can cause damage to your acoustic instrument, leading to warping, shrinking, and cracking.

Not only does it ruin the aesthetics of your instrument; over time, it can destroy its tone or ultimately make it unplayable. Boveda's unique product uses a specially formulated solution of pure water and natural salts encapsulated in a vapor-permeable membrane to maintain a constant relative humidity level of 40-50% when placed next to your instrument in its case, preventing devastating moisture swings. You can be confident that your instrument is kept in an ideal environment. When your packs are saturated and firm, simply replace them with Boveda replacement packs. This replacement pack includes a total of 4 packs with a relative humidity of 49%, each with a shelf life of 2 years; so you can have them on hand whenever you need!