Omega “Speedsonic”

European Watch Clock and Jew e11ery Fair 1974 BF 310
The electronic chronograph : one of the major new developments on display at the 1974 European Watch, Clock and Jewellery Fair. This Omega Speedsonic model is equipped with a sonic resonator (tuning-fork) movement with a frequency of 300 Hz. Its features include anhour register, a minute register, a small second hand and a day and date calendar. (OMEGA “Speedsonic”)