My sister had one of these -- a kid's version of a bolo, which is actually some sort of South American weapon. If it can kill animals, it must make a perfect toy for kids! I knocked my brains out with a pair of Clackers once and refused to go near them ever again. (If I didn't bury them out in the backyard, I should have.) Two glass, often glitter, balls on a string with a key in the center and you banged them together clackers two glass often,ball on a string with a key in the center and you banged them together You describe "Clackers" as glass. They were actualy a very hard brittle plastic. This material often shattered and was capable of inflicting serious injury to the face, particularly the eyes. I for one loved them!