The fact that the fingers can&#39;t be crossed often limits the improvement of the performance level, and insisting on training to improve the basic skills is the king. This span trainer is continually improved to help the player solve the problem of the fingers being unable to open and increase the flexibility. It can be carried around when you are free to play the piano/guitar.</p> Features: High toughness, elasticity, smooth surface, easy to clean, and constant. The spreader is used without a piano/guitar, so it is easy to carry around. Improve finger span and flexibility, improve finger function and improve playing efficiency. The use process does not affect other activities of the finger.</p> Specifications: Main color: white Main material: plastic Hole: 25mm+25mm+25mm+20mm, 20mm+20mm+20mm+18mm (optional) Package size: 210 * 100 * 25mm / 8.3 * 3.9 * 1.0in Package weight: 33g / 1.1ounce</p> Note: Please allow a little difference due to manual measurement.</p> Package list: 1 * Finger Expansion Tool</p>