3.5" with his well-done portrait on an interestingly designed button with rim reading "S '72/Delthesians" plus the name "Dudley" on a ribbon below his portrait. There is text on the curl but most of it is below the edge of the metal reverse although the words "Creative Promotions" can be deciphered. Button surface has three microscopic air bubbles and extreme rim edge has 3 essentially pinpoint rub marks of little consequence. Button displays bright and clean. Only example we've seen. Exc.