It is made of natural stones. The stones are oblong or oblong, and the middle section is slightly thinner, generally 12 cm to 14 cm in length, 4 cm to 6 cm in width, and 1 cm to 1.2 cm in thickness. vice. It is better to use pebbles that are smooth and without edges and corners. The stone is hard and not easy to break. When playing, the performer holds two pieces in each hand, with the p...