Keep your instrument in peak condition with the D'Addario Two-Way Humidification Replacement 12-Pack (PW-HPRP-12). Designed for use with D'Addario's Two-Way Humidification System, these replacement packets automatically maintain the ideal humidity level for your acoustic guitar or other wooden instruments.

Using advanced two-way humidity control technology, each packet adds or removes moisture as needed to maintain a stable environment of approximately 49% relative humidity. This helps protect your instrument from the damaging effects of seasonal humidity changes, including cracks, shrinking, swelling, warping and fret sprout.

The replacement packs require no maintenance, water or activation—simply install them into your existing D'Addario humidification system and replace them when they become firm. Supplied as a convenient pack of twelve, they're ideal for musicians with multiple instruments or for keeping spare replacements on hand.