Note: Please allow slight size error due to manual measurement. Thanks for your understanding. specification: Item Type: Finger Exercise Ball_x000D_Material: PU Sponge_x000D_Size: Approx. 11 x 10 x 7cm / 4.3 x 3.9 x 2.8in_x000D_Hardness: 20LB_x000D_Purpose: Grip strength training, grip strength rehabilitation, leisure play Features: 1Cross Finger Design: If the user's fingers are not flexible, the cross finger design can effectively prevent the ball from falling off. 2Increase Finger Strength: Squeezing them to increase the strength and endurance of the hands, fingers, wrists and forearms. 3Easily Exercise Anytime and Anywhere: Finger strengthening ball is light in weight and can be carried in a bag, suitable for many occasion, such as school, home, office, etc. 4Wide Range of Application: Suitable for elderly rehabilitation training and muscle vitality training. Especially suitable for people with ADHD, obsessive compulsive disorder, autism or high anxiety. 5Excellent Material: Made of high quality PU sponge material, safe and eco friendly, slow rebound, soft and durable for long term use. PackageList: 1 x Finger Exercise Ball