My father discovered this on a trip to Chicago long ago, and brought a few home to Massachusetts. They were great for playing in our yard, where the fence was

My father discovered this on a trip to Chicago long ago, and brought a few home to Massachusetts. They were great for playing in our yard, where the fence was too close for a real softball, but these are much harder to hit >100ft so they let us use the whole yard. We always called them "Chicago softballs"