SUNVP Therapy Hand Squeeze Exercise Balls Combo Kit Fitness Restore for Stress Relief and a Stronger Grip (Pack of 3 with Color Card Packaging), Blue, Purple and Lemon, Circular Includes 3 therapy grip balls are color coded - lime,purple,blue (soft, medium, and firm and full-color illustrated exercise guide) Rubber (TPR), Blister and color card packaging for easy storage and travel Develop and strengthen grip, hands, fingers, wrists. Prevents stiffness, increases flexibility. Relieve stress and muscle tension from computer work,relieves joint pain Suitable for home, travel, office occasions etc.