2.25" from early 1900s with covered tin back stamped by maker's name St. Louis Button Co. plus a long vertical stickpin. Front shows machine which has numerous blades all tipped with a red color accent surrounded by text "Althouse Wheeler Co.-Waupun, Wisconsin/Perfect Self-Governing In Any Wind-Never Blows Down." Cello surface has slight scattered bumpiness to the touch but remains totally clean and glossy. Among the rarest of the windmill buttons and we recall seeing only one other over four decades. Rare.