Feature: 1. Made of steel material, this musical instrument sends out crisp and ethereal sound, featuring fine flexibility and long service life. 2. Processed with electroplating workmanship and anti-rust treatment, the surface is shiny and translucent. 3. Each key, with 4mm width and 1mm thickness, is comfortable to play, providing great playing experience. 4. The lettering on the back of each key helps you quickly find the corresponding key during installation. 5. A perfect gift for family and friends. Specification: With this set, you can assemble a 21-tone thumb piano with kids to develop their hands-on ability and musical sense. Features: The corresponding tunes of the metal tines are 1(D2), 2(B7), 3(G5), 4(E3), 5(C1), 6(A6), 7(F4), 8(D2), 9(B7),10(G5),11(F4),12(A6),13(C1),14(E3),15(G5),16(B7),17(D2),18(F4),19(A6), 20(C1), 21(E3)(from left to right). Made of steel material, this musical instrument sends out crisp and ethereal sound, featuring fine flexibility and long service life. Processed with electroplating workmanship and anti-rust treatment, the surface is shiny and translucent. Each key, with 4mm width and 1mm thickness, is comfortable to play, providing great playing experience. The lettering on the back of each key helps you quickly find the corresponding key during installation. A perfect gift for family and friends. Specifications: Material: Manganese steel + solid wood Number of Keys: 21 21-tone(from left to right): 1(D2), 2(B7), 3(G5), 4(E3), 5(C1), 6(A6), 7(F4), 8(D2), 9(B7),10(G5),11(F4),12(A6),13(C1),14(E3),15(G5),16(B7),17(D2),18(F4),19(A6), 20(C1), 21(E3) Key Width: 4mm Package Size: Approx. 230*100*25mm / 9.06*3.94*0.98in Package Weight: Approx. 165g / 5.82oz Packing List: 1 * Set of Shrapnel 6 * Screw 2 * Sleeper 1 * Tuning Hammer Package List: 1 * Set of Shrapnel 6 * Screw 2 * Sleeper 1 * Tuning Hammer