It's Duncan Yo-Yo Top Time! store poster from the 1950s. Posters such as these were usually taped to a store front window or near a Duncan yo-yo display inside the store.
Base on the yo-yo image and the use of a single red color for the text, this simple poster is likely from the 1950s.
See also the four-color Dell Big "D" Yo-Yo poster that has similar dimensions to the poster in this exhibit.
