This item is stringed instrument . It will facilitate your violin, erhu, viola or cello to bring excellent sound and chord grip. And bright sound, you can beautify the sound of your instrument. , reduce harm to . Features -Color: Black -Material: -Size: About 4.00X4.00X1.50cm/ 1.57X1.57X0.59in - , less dust, and a viscosity, which can help you maintain your instrument well. -Super sensitivity, can make the instrument sound , pure and moving tone, reduce noise when playing. -Strong grip, strong sound penetration, warm and bright tone, suitable for all kinds of steel strings and synthetic strings, especially for cello and bass. -Low-dust design, environmental protection, for musicians to use, it is a must-have product for people who love musical instruments. -High sensitivity, voice, reduce noise, produce clear and moving sound. Package list: 4 x rosins