4Piece Acoustic Instrument Humidifier Set Keep hollow body string instruments stable and playable in dry conditions. This fourpiece humidifier set is designed to sit in the sound hole and gently release moisture to the instrument body, helping to reduce wood shrinkage, cracking, and changes in action and tone caused by low humidity. Key benefits Prevents moisturerelated damage: Maintains interior humidity to reduce the risk of cracking, warping, and fretboard shrinkage common in dry environments. Simple and reliable: Easy to use design that delivers controlled moisture release without complicated setup or electronics. Multiple pieces for flexibility: Four humidifiers let you protect multiple instruments or keep spares for travel and seasonal use. Broad compatibility: Suitable for acoustic guitars, classical guitars, ukuleles, mandolins, violins, and other hollow body string instruments with a standard sound hole size. Compact and unobtrusive: Fits inside the sound hole and stays out of the way while you store or play the instrument. Main features Function: Adds and maintains moisture inside the instrument body to stabilize wood and help preserve the instrument structure and tone. Compatibility: Designed for use with acoustic and classical guitars, ukuleles, mandolins, violins, and similar hollow body instruments. Size and fit: Compact form intended to fit most standard sound holes and sit securely without rattling. Material and construction: Soft, absorbent interior with a protective outer layer for controlled evaporation and gentle contact with the instrument . Performance: Delivers steady moisture release; refillable and reusable for ongoing humidity control. How to use Soak the humidifier in water until saturated, gently squeeze to remove excess, then insert into the instrument sound hole and position against the inside . Refill as needed based on local humidity conditions and frequency of use. Keep a set in instrument cases, storage rooms, or near performance areas to maintain consistent humidity. Practical scenarios Home storage during winter: Use in instruments kept in heated rooms to reduce drying from indoor heating systems and seasonal humidity fluctuations. Travel and gigs: Carry a humidifier in your case when moving between venues, flights, or airconditioned spaces to help protect instruments on the road. Offseason preservation: Place inside instruments during periods of longterm storage to help prevent cracks and structural changes before the next use. What makes this set stand out Four humidifiers provide flexibility for multiinstrument owners, teachers, or technicians who need to protect several instruments at once. Userfriendly design suited to both beginners and experienced players, with no special tools or installation required. Neutral, compact profile that protects instruments without interfering with playing or storage. Package includes Four instrument humidifiers, ready to soak and use. Note Refill frequency depends on local climate and instrument case seal. Monitor humidity and condition of the instrument regularly and adjust use as needed.