Cal. 12 HU nickel-finished lever movement 18 jewels bimetallic compensation balance silvered matte dial black hard enamel Roman numerals gold hands outer revolving silvered and black ring for the diurnal and nocturnal hours separated by stylised gold sun and moon circular case wide revolving bezel engraved with the names of 30 world cities teardrop lugs snap on back engraved John T. Ryan 18K gold Patek Philippe buckle case dial and movement signed