These are replacement pieces for a fun game called Otrio. Otrio is a game with a fun twist to tic tac toe. To learn more visit there website at https://otrio.com/pages/how-to-play You can find a lot more cheaper options off of Amazon than there Official website. This model is based on the Marbles Brain Workshop game board, however, it may work with other game boards. If there is any problems with the files, please point it out so I or someone else can fix it.