Description: 【Universal Expander】: The multi functional tool is designed to help beginners stretch their fingers and help them play guitar, piano, guzheng, violin, erhu and other musical instruments. 【Durable Material】: The rings of the finger dilator is made of durable material and copper nut material, and the inner rod is made of high fiber and silicone tube cover. These materials ensure durability and comfort during use. 【Easy to Use】: The piano finger expander can be used as a guitar extender, lightweight and easy to use. 【Adjustable Span】: This large grip strength trainer has an adjustable span feature to meet the needs of different users, making it the accessory for any instrument player. 【Package Includes】: Every purchase comes with a finger extender tool to help you on your musical by effectively training your fingers. Specification: Material:Fiber Silicone Size Chart: Total Length of Rings: 20cm/7.87inch L Inner Diameter: 2.3cm/0.91inch M Inner Diameter: 2.1cm/0.83inch S Inner Diameter:1.9cm/0.75inch Package Includes: 1 Guitar Finger Expansion,(4 Pack) Note: Please allow 1-3mm measuring deviation due to manual measurement. Due to the different monitor and light effect,the actual color of the item might be slightly different from the color showed on the pictures.Thank you!