The D’Addario Acoustic Guitar Humidifier Pro offers a simple, reliable way to protect acoustic instruments from the cracking, warping and fret issues caused by dry air—and this convenient 3-pack ensures you can safeguard multiple guitars or keep spares ready for seasonal changes. Each unit uses a hydrophilic sponge that holds up to 12 times its weight in water, providing long-lasting moisture without constant refills. The design hangs safely between the strings, never touching the guitar’s finish while dispersing humidity evenly inside the body. A built-in stopper makes it easy to check moisture levels at a glance, so upkeep stays quick and stress-free. Whether you maintain a collection, manage multiple stage guitars or want backup units ready to go, this 3-pack delivers consistent, low-effort protection to keep your instruments playing their best all year long.