The fact that the fingers can'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. Features - Color: Green. - Material: ABS. - Size : About 13.50X2.50X1.00cm/5.31X0.98X0.39in - Size L: About 14.50X2.50X1.00cm/5.70X0.98X0.39in - High toughness, elasticity, smooth surface, easy to clean, and constant - The spreader is used without a piano, so it is easy to carry around - Scope: electric guitar, bass, ukulele, piano, saxophone, instrument keyboard - Simple and light, easy to carry, practice anytime, anywhere - Improve finger span and flexibility, improve finger function and improve playing efficiency Package list: 1 x Finger Expansion Sleeves