DescriptionMade of premium materials, comfortable and elastic enough to use. The piano training balls have different functions that can be changed to different wrong piano gestures. They are so small and light that they can easily be carried around in a bag and used at any time.Features- Color: Random Color - Material: Sponge - Size: 6.00X6.00X6.00cm/2.36X2.36X2.36in -A ball in hand can solve the problem of piano player hand shape, helping to form correct piano gestures.- All kinds of training methods are suitable, used for all kinds of hand shape exercises.- These ball are suitable for tiger opening expansion, finger strength improvement, palm support and wrist lifting.- Practice five minutes a day with these practical training balls for good piano playing gesture.- With high elastic sponge material, these piano finger trainers are comfortable to touch, quick rebounds.