Illinois Watch Company Bunn Special (18-size)

The Bunn Special (18-size) is a manual-winding movement manufactured by Illinois Watch Company from 1895 to 1927. It was produced in 21-jewel and 24-jewel variations, each adjusted for temperature, isochronism, and positions. The movement was available in hunting case (Model 5) and open face (Model 6) configurations. Recognized as a railroad-grade pocket watch, it remains a sought-after example of American high-grade watchmaking from the early 20th century.