Applicable Scenes: Ergonomically designed to fit small to medium hand sizes. Perfect for men, women, and seniors. Fine workmanship and stylish design. Built-in button cell battery; if used for 3-4 hours per day, the battery will last approximately one year. Great hand strengthener for musicians, including drummers, guitar, piano, and violin players. Ideal for athletes and sports enthusiasts looking to increase hand, wrist, forearm, and finger strength for activities such as rock climbing, bodybuilding, golf, and tennis. Color: Green Material: Spring steel + PP Size: 17 x 12.6 x 2.6 cm Package Contents: 1 x Grip strength trainer Note: Only the items listed above are included. Other products are not included. Light reflection and differences in display screens may cause slight variations in color compared to the actual product. Measurement error allowance is +/- 1-3 cm.