You can assemble this thumb piano with your child to develop his hands-on ability and musical sense. Features: Includes all parts to built a complete thumb piano, pure hand-made and fine workmanship. With smooth surface for DIY painting, you can draw patterns you like on the thumb piano. You can enjoy the fun of DIY and make a thumb piano with your children or friends. Assemble their own, easy to install and learn. Specifications: Key: 10 keys, 17 keys (optional) Material: wood, metal Item size: 10 keys: 167 * 125 * 35mm / 6.6 * 4.9 * 1.4in 17 keys: 177 * 125 * 45mm / 7.0 * 4.9 * 1.8in Item weight: 10 keys: 142g / 5.0ounce 17 keys: 167g / 5.9ounce Package size: 10 keys: 180 * 130 * 40mm / 7.1 * 5.1 * 1.6in 17 keys: 180 * 145 * 50mm / 7.1 * 5.7 * 2.0in Package weight: 10 keys: 294g / 10.4ounce 17 keys: 350g / 12.3ounce Note: You have to assemble the keys yourself. Packing List: 1 * 1 * Installation Kit