Yes, boys and girls, that is something we used to play with back in the 70's.  It was our version of today's fidget spinner.  This however was more deadly, it is called a "Clacker".  It was basically to hard plastic balls on opposite ends of a string with a ring in the middle for your finger.  A little wrist action and you were the new neighborhood ninja.  My friend Sam and I were discussing what our favorite toys were when we were growing up.  I had a hard time deciding between the full size G.I. Joe action figure or my "Johnny Lightening Race Track".  His was plastic army men from the civil war period and guns that shot plastic bullets.  One thing we did agree on was playing outside.  If you were bored, you were sent outside to find something to do.  A shovel got you a hole which turned into a fort.  a couple of boards, 4 wheels and nails and rope and you had a go-cart ready to go from the top of the highest street in your neighborhood. I suppose if we would have kept some of those toys they would be worth some money today.  But the memory is priceless.