48.00 mm case diameter, white double-sunk dial signed ILLINOIS, Arabic numerals with red and black outer chapter ring calibrated to 60 units, blued steel spade hands, subdial for seconds at 6 o'clock, guilloche engraved case with blank cartouche, stem wound and set 21 jewel nickel movement adjusted to temperature, isochronism and six positions signed ILLINOIS WATCH Co. SANGAMO SPECIAL. 
Movement number: 2790661.
Inner case back stamp: PHILADELPHIA WATCH CASE CO TWENTY YEARS 9063628.