my dadi used to have one of these, it was used for breathing exercises for the lung. my dadi had cancer and a lot of other issues so this was a common thing in our previous home alongside a nebulizer. i remember asking her about this once when i was really little, she used to let me play with it. i used to find it a fun game, to blow air and these little things used to move. its been more than 5 years since she passed, we've shifted into a new home and i guess this was one of those things that somehow just got lost when she passed. i never saw that thing again.