Popper knockers
Appearance
'''Popper Knockers Vintage Toy''' from the 1970's, briefly popular in the early 1970s. They are formed out of two hard plastic marbles, each about two inches in diameter, attached to a ring with sturdy string. The '''Popper Knocker''' Brand were maunfactured in '''Carterville, Missouri (On Route 66),''' they were packaged in Joplin, Missouri. Popper Knockers were eventually discontinued after children got injured whilst playing with them: besides being fairly heavy and fast-moving, the spheres, being made of hard acrylic plastic,looking and feeling very similar to Glass could shatter upon striking each other.
They can be found for sale as Collectors Items and viewed by clicking the number 1[1].