Finger Strengthening Exerciser Balls Design: This finger ball exerciser provides the right amount of resistance to strengthen the hand. These hand strengthener grips are effective for maintaining a secure hold during exercise, without binding or interfering with finger alignment. Customized Individual Five Fingers Buttons: Each finger button is easily adjustable to increase the pressure required to press each plunger. The silicone rubber pads are comfortable on the palm and fingertips. Better for Improving Strength & Dexterity: This is an easy and painless way to strengthen fingers and hands, suitable even for individuals with arthritis. It allows for comfortable squeezing, unlike some other exercisers. Real Finger Strength Training: These hand exercisers are ideal for guitarists, office workers, pianists, musicians, artists, craftspersons, woodcarvers, web designers, and others. A useful tool for building finger strength. Color: Black Material: ABS + Silicone Package Contents: 1 x Finger Exerciser Only the above package content is included; other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture to appear slightly different from the real thing. The measurement allowed error is +/- 1-3 cm.