1.75”. Reverse has a metal insert used to hold a suspended fabric ribbon although the suspended part of the ribbon is gone with just traces remaining behind the metal insert. Metal has trace of a paper label but not enough text to make out a name. Cello has single pinpoint rub just above the horn on left edge. All else is essentially Mint. c. 1900. Hake book Collectible Pin-Back Buttons photo example Cattle #96. Comes with Hake’s COA.