Designed to work with Planet Waves Guitar Humidifiers.
The Planet Waves GH-RS Guitar Humidifier Replacement Sponge 3Pk is designed to work with Planet Waves Acoustic Guitar Humidifiers (see our SKU# 420552). Together, the system protects your guitars from damage even in the driest conditions. The moisture reservoir is suspended inside the body, the system releases moisture evenly and slowly inside your guitar without actually touching the instrument. These high absorption sponges maintain proper humidity levels and are quick and easy to refill.