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. It can be carried around when you are free to play the piano/guitar. Features - Color: White. - Material: ABS. - Size: 20.00 x 2.30 x 2.30cm/ 7.86 x 0.90 x 0.90 inch. - The adjustable extender tool is mainly fit for instrument beginners of adults plus standard when practicing their instruments. - It helps with extending your fingers for playing the guitar bass and musical instruments. - Choose the suitable support rod and use the included screwdriver to adjust the distance between the rings until it suits you. - The set includes 4 protectors and a set of adjustable extender tool. - Relieve when novices practice and strength. Package list: 3 x expander