Colorful 1.25" which originally had a backpaper advertising the product although that is not present on this example. Although without backpaper, the thin collet has stamped-in name of the maker and patent date reading "Phelps Patent 1899." Reverse has tiny 1/8" cello split along the collet with a little tan stain in this area but the stain does not extend to the face of the button which remains extremely clean. We've seen only a few. Displays N. Mint.