For the humidification and maintenance of the violin, the special non-vinyl and anti-desensitization resin material is used to good toughness when passing through the F hole, and to minimize the contact with the inside of the instrument. The moisture indicator uses water absorption The material can absorb moisture more than 10 times its own weight, and discharge it from the hole of the pipe in the form of gas Product:Violin Humidifier Colour:Green Material:Special non-vinyl and anti-desensitization resin Size:0.6x1.1x31.1cm Package Contents: 1 * Violin 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.