Clackers (also known as Clankers, Ker-Bangers, and numerous other names) were toys popular in the late 1960s and early 1970s. In 1968, tempered glass sphere models emerged that would eventually shatter, sending glass shards into the face of the user and anyone nearby. In the early 1970s, manufacturers changed them to plastic spheres suspended on each string. When they were swung up and down, banging against each other with a lot of force they made the loud "clacking" sound. Clackers are similar in appearance to bolas, the Argentine weapon.