Super balls became very popular in the 1960s. The surprising bouncing behaviour of these balls appealed to young and old. The header card with this particular ball makes it clear that it is a Berwick toy. The ball itself has writing on it including WHAM-O MFG. CO. San Gabriel. Calif. Also illustrated here is the back of the header card which contains detailed information on the material Zectron from which the ball is made.