Feature 1Preventing Cracks: The guitar sound hole humidifier with even humidification that will not damage the body of the piano, preventing cracks and deformation. 2Multiple Hole Distribution: The guitar sound hole humidifier with a multiple hole distribution design for extended humidification cycles and balanced humidification. 3Integrated Sponge: The guitar soundhole humidifier has an integrated sponge for balanced humidification and can be filled with water on both sides. 4Easy To Use: The guitar soundhole humidifier is simply wetted with a sponge, placed in the included hygrometer and fitted into the soundhole of the guitar. 5Environmental Friendly: The guitar sound hole humidifier sponge is long lasting and can be easily refilled with water as needed, making it a cost effective and environmentally friendly solution.Item Type: Guitar Soundhole HumidifierMaterial: ABS and MetalSize: Approx. 11cm / 4.33in .wang-edit-text{ font-family:'Arial' !important; } .wang-edit-text table { border-top: 1px solid #000; border-left: 1px solid #000; } .wang-edit-text table td, .wang-edit-text table th { border-bottom: 1px solid #000; border-right: 1px solid #000; padding: 3px 5px; } .wang-edit-text table th { text-align: center; }Package List1 x GuitarSoundholeHumidifier1 xOther Accessories