Clackers are the toy with a jillion names. It was essentially two large marbles attached by a sturdy string with a ring in the center. You would put your finger in the ring allowing the marbles or balls to hang below. Here is where the fun starts. The idea was to get the two balls tapping (or clacking if you prefer) against each other by pulling up on the ring lightly. Once you got the hang of it, you could get them going faster and faster until they were smacking each other above and below your hand in a stunning arc. These toys are now legendary. They started finding their way into the schoolyards in the early seventies and in 1971 were yanked from shelves because kids were suffering eye injuries when the fragile, glass-like balls were shattering from the violence of contact with their mates. I believe a plastic version may have been released after the original and the more menacing version was pulled, but I don't think that it enjoyed the same popularity. One of the main obstacles in locating this toy today is knowing what to call it. There were supposedly over 80 copy-cat products on the market during Clackers hey-day. During your search expect to see names like: Bonkers Clackers Clack Clacks Click Clacks Crackers K-Nokkers Ker- Knockers Klackers Klick Klacks Knockers Mini Poppers Moon Rocks Popper Knockers Rockers Super Clackers Quick Klacks Quick Clacks Quick Wacks Wackers Whackers Whak KOs Because of the abrupt halt in production and distribution there were truckloads of these toys dumped on the secondary market. This is good for collectors today because it means that there are lots of these toys out there still MIP selling in the $10-$20 range.