... diameter, soft & squeezable, easy for stress, with spiky outside the ball, exercise hands & fingers, differ color available. 1. 7cm diameter, another ... to stress, good for exercise fingers, a kind of massage ball.5. product comply EN 71 & ASTM stardard.6. small parts ... .7. packing 1pc/polybag, 12pc/PDQ, 72pc/ctn. stress exercise ball