What the Duncan "Imperial" yo-yo was to kids in the USA, the one-piece Elfverson "Pro" yo-yo (and "Olympic" model) was to kids in Canada. These very popular, classic wooden yo-yos were typically a Canadian player's first introduction to yo-yo.
In 1978 National – the Olympic and Pro yo-yo distributor from 1968-1977 – became the Parker Brothers Company. Parker released this particular version of the Pro. It included an updated stamped seal with the Parker name added to it. Approximately 585,000 Pro Tournament yo-yos and 285,000 Olympic yo-yos were made.
Compare with similar versions from National, Canada Games, Playtoy, and Irwin Toys.
