For sale is a 1920s MECHANICS OCTAGON LINE & SURFACE LEVEL made by Frank B Hall, Geneva, Ohio. This handy aluminum pocket level is in its original lithographic tin which features a detailed graphic of the level. The carry case is marked with a 1921 patent date. The tool’s level bubble is intact. Tin carry case has wear consistent with its age. The pocket tin measures about 3 3/4 inches long. A top rate collectible tool.