7/8" with back paper naming both wagon maker and also W&H as button maker. The collet has narrow and wider areas and originally held a wire for either money clip or shoe button hook. The wider area has tiny nicks but is intact and the cello remains Mint. Back has standard brass spring pin. Only example known to us. From color plate page #152. From Phila. firm "Fulton & Walker" with slogan "Best Wagons For Business". Comes w/Hake's COA.