Perfect Stress Relief Ball - It can greatly relieve daily stress and strengthen your hands, forearms and fingers with simple exercise. Increase flexibility, improve strength, prevent stiffness, and relieve joint pain in your hand, wrist, and forearm. This finger therapy balls also can help prevent mouse hand and reduces anxiety and increases blood flow and circulation throughout your hands, arms and fingers. Five strengths levels - This package comes 5 hand therapy balls with different colors and 5 types strengths levels are contained. The color coded set includes yellow(extra soft), orange (slightly soft), a red (moderately hard), blue (firm resistance), green(extra firm). Please choose a suitable resistance according to your own need. Fit for men, women and children. Durable material - Made of 100% thermoplastic rubber (TPR), hypoallergenic, nontoxic, reusable, recyclable, and phthalate and latex fee. Our stress relief balls are lightweight, durable, and safe for kids and adults alike. Wash with warm soapy water to clean. Wide range of use - It would be a wonderful hand exerciser for people who often do typing, driving, writing, climbing job for long time, also workable and benefited for stroke rehab patient. With exercise and training, you will make gradual progress of finger for guitar, piano, violin and rock climbing.Nice training ball for hand injury.