a large gold chronograph wristwatch, Eberhard & Co., 'Extra-fort' circa 1950

18k, nickel lever movement, mono-metallic balance, silvered dial, applied Arabic and baton numerals, outer ring calibrated for tachometer, three subsidiary dials indicating constant seconds, 30-minute and 12-hour registers, large circular case with single button chronograph and locking button in band, case, dial and movement signed.