Kalimba forms for 3D printing. ABS plastic is suitable for printing. Also, forms can be cut from acrylic. One-piece mold size: 13.5x18x3cm Hollow molds size: 15x20x4cm The dimensions can be changed. Sizes fit for 21 keys. Kalimba is an African musical instrument with a fascinating, attractive sound similar to the sounds of a music box. The instrument is attractive in that it is not necessary to know the notes to play it.