The grip ball of e-gg shape is comfortable to hold in hand, well rebound resilience fits for hand therapy and stress relieve. There are different resistance levels of different colors for your choice. Features: E-gg shaped for a comfortable fit in your hands. Made of high-quality skin-safe silicone, well rebound resilience. 5 types of resistance levels, you can choose the strength of the grip ball according to your needs. Easy hand exercises and finger exercises help strengthen your hands and fingers, increase your r-ange of motion. Relieve muscle tension and ease stress when squeezed or manipulated by the hand and fingers. Specifications: Material: Silicone Color: Yellow, Orange, Red, Blue, Green (optional) Resistance Levels: Yellow--15KG (33 pounds) Orange--20 KG (44 pounds) Red--25KG (55 pounds) Blue--30 KG (66 pounds) Green--35 KG (77 pounds) Item Size: 55 * 44mm / 2.17 * 1.73in Package Weight: 55g / 1.94ounces Package Size: 53 * 53 * 53mm / 2.09 * 2.09 * 2.09in Packing List: 1 * Grip Ball