This D'Addario Humidifying system protects your acoustic guitar from damage even in the driest conditions. Suspended by the strings, this system never touches the guitar body. Exclusive non-drip design releases moisture evenly and slowly and recharges easily with a syringe, without removing the humidifier from the guitar. The D'Addario Guitar Humidifying System protects your guitars from damage even in the driest conditions. With the moisture reservoir suspended inside the guitar body, the D'Addario Guitar Humidifying System releases moisture evenly and slowly inside your guitar to maintain the proper humidity level.