A nicely carved old one, walnut I believe, and just the sort one wants to keep on the desk to pick up and watch those balls roll back and forth while thinking about other things. And while the posts of the "cage" are near straight, the hand of the maker is felt all over this. C. early 20th century I believe, with nice general wear to the edges/corners, just as there should be.
3 3/8" x 7/8" x 7/8". Very good condition.