This soundhole humidifier ensures your acoustic guitar stays in top condition. It provides essential moisture to prevent the wood from drying out, cracking, and other damage. Easy to install and remove, the humidifier is a convenient addition to your guitar maintenance routine. Guitar Room Humidifier Dimensions: 8.50 x 5.50 x 3.50 cm / 3.34 x 2.16 x 1.38 inches Multi-functional: This versatile humidifier is ideal for maintaining your acoustic guitar. Guitar Humidifier Soundhole Cover Set Crack Prevention: Humidifies the soundhole to prevent winter cracks. Soundhole Humidity Easy to Use: Easy to install and remove, suitable for guitarists of all levels. Cello Humidifier Guaranteed to withstand daily use. Violin Humidifier Instructions: Use the humidifier to humidify your guitar when the humidity is below 40%. When the humidity is above 75%, remove the absorbent pad, keep the humidifier box dry, and add dehumidifier to dehumidify the guitar. The humidifier's scientific design of silicone and plastic allows it to securely clamp to the guitar's soundhole panel. The humidity meter rotates 180 degrees, allowing you to humidify while playing and better monitor the humidity. The humidifier cover is removable and the absorbent pad can be replaced to prevent mold. Color: Black Material: plastic Package Contents: 2 x Guitar Humidifier Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.