[Built-in Piano ]: This piano hand shape corrector and strengthener comes with a built-in piano , allowing you to perform a mini concert anytime, anywhere. Even without a physical piano, you can still and practice techniques while training your ears. [Integrated Speaker]: Equipped with a dual voice coil strong magnetic speaker, this device delivers loud volume and clear sound quality. This enhances your practice sessions and makes them more enjoyable and effective. [Piano Hand Shape and Strength Training]: Designed to mimic the shape of a piano hand, this device helps to correct your hand shape and make your training more scientific and precise. It promotes relaxation of the hand muscles and encourages more scientific force application, enhancing coordination and doubling the efficiency of your practice. [Non-Slip Silicone Keys]: The device features supportive silicone keys that prevent slipping and collapse. This design ensures a comfortable and effective practice session, helping you to improve your piano playing skills. [High-Quality Springs Inside Keys]: The keys of this device are equipped with high-quality springs that provide sufficient rebound force. This feature ensures a realistic piano playing experience, helping you to build strength and improve your piano playing technique. Horn: 0.5W Sound: piano sound Battery: 3 AAA dry batteries (not included in this product) Product size: 12.2 x 10.2 x 6.2cm/4.8 x 4 x 2.4inch Item weight: 140g/4.9oz Note: Due to the different display screen and light effect, the actual color of the item might be slightly different from the color showed on the pictures. Color: A:Black Material: ABS+silicone Package Contents: 2 * Piano Finger Exerciser Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.