8 Hole Grip Ball Fitness Child Strength Trainer Hand Muscle Strengthener. Grip Thumb Strengthening Devices Hand Strengthener Finger Grippers. - Multi-function: suitable for all kinds of balls, inflatable toys, inflatable sofas, yoga balls, swimming circles, yoga ball, balloon, fitness ball, inflatable spring horse, balance trainer, ball, constant speeds jump ball, horse yoga ball, bed, air pump accessories.
eBay