Features: Sound hole cover designed for EQ folk guitars(sound hole dia.10cm). For eliminating unwanted feedback in amplified live performance. Also for Adjusting the guitar volume by rotating the backside cover. Quick and easy to install remove, helpful to protect the sound hole. Soft rubber covers the insert edge, no damage to your guitar. Specifications: Material: Plastic 43; Rubber Compatible Sound Hole Size: Dia 10cm / 3.9in Item Size: 11 * 1.5cm / 4.3 * 0.6oz Item Weight: 48g / 1.7oz Package Size: 14 * 12 * 3cm / 5.5 * 4.7 * 1.2in Package Weight: 71g / 2.5oz Note: This sound hole cover is not suitable for guitars whose fretboard has reached the sound hole. The guitar showed in the picture is not included. Package List: 1 * Sound Hole Cover