Yes, you read it correctly - these little dynamic balls are made of recylced street sweeper bristles!  As Aaron Kramer says, "Trash is a failure of the imagination."  The inside movable ball is "money" wrapped. And, the "piece de resistance?"  Some would say it is the buttons.  Buttons from Mrs. Howard, who passed away leaving her long collected button collection to Kramer to "spread all over the world in his art."  This little Fun Spheroid is 3.5 inches diameter.  Addition available sizes are, 4.5" and 6" diameter.