The instrument looks great and does its job (noises) as expected. However, I have a couple of critical remarks: - I understand that the balls are a kind of natural walnut, hollowed out and then processed. However, between the two instruments purchased there is a significant difference in the sizes of the balls. They feel different in the hands, which makes it uncomfortable to use - there are some areas that stick a bit, both at the cap where the string is hooked, and on the opposite side of the balls, where there is a tip that can pinch - the length of the string between the two instruments differs by about 1 cm. Again, inconvenient. It would be preferable to have a clear standard of dimensions.