I was going through my treasure jars I keep (full of little things I like) and I found these little foam bullets with a suction cup on the end. The rest of the toy is long gone, having seen better days.
I snapped off the end of the foam bullet and what I found was a little foam hollow tube. I used it to make my pens easier to hold.
I am always happy when I can recycle things, yet again, and reuse them time after time. You could probably put this in the jewelry box and put rings on it, if the rings are small enough.