Just What is This Round Object?

Radio stations are notorious for accumulating "junk." Usually it is promotional items or signage, and the junk is kept for future use and most likely will never be used again. Recently, one of our staff members got energetic and cleaned out the Y101 storage area, and in doing so came across a box. That box ended up in my office with what looks like ping-pong balls in it.

The problem is they are not ping-pong balls. Now, I know what they are, but I thought I would have some fun and ask you for your thoughts on what you think these styrofoam balls were used for in the past. As you can see, they are three times the size of a nickel and are very light.

So why would a radio station have a need for these little round objects? Any thoughts? Let me give you one hint. They were designed for cars.