Features: 1.High Quality Material: The hand training balls are made of high quality TPR material. Highly flexible and durable, it makes a perfect gift for family and friends as a unique and practical item. 2.Advanced Finger Trainer:The egg-shaped grip ball has a strength of 15kg.It is perfect for stress reduction, recovery and training finger strength and dexterity. 3.Function: A few simple exercises will train your fingers, palms and forearms. Ideal for improving dexterity, finger strength and motor skills. How to use: Simply hold it in your hand and squeeze. Trains your forearm strength easily and effectively. 4.Versatile Use: Use this anti-stress ball kneading ball to relieve mental stress, increase hand, finger and forearm strength, improve manual dexterity and prevent osteoarthritis. Suitable for use by athletes of all ages, mountain climbers, office workers and pianists. 5.After-sales Service: If you have any problem, please contact us immediately, we will help you solve it as soon as possible. Specifications: Diameter:4.5cm Material:TPR Notice: 1.Actual color may be slightly different from the image due to different monitor and light effect. 2.Please allow 1-3cm deviation due to manual measurement. includes: 1 or 3 Hand Exercise Ball