Tissot “Tissonic”

European Watch Clock and Jewellery Fair 1974 BF 308
A newcomer among sonic resonator watches, this Tissonic has a tuning-fork that vibrates 300 times each second. Its rate stability is impressive and its in-wear accuracy averages one minute a month. Elegantly designed case, water-resistant to 3 atmospheres (a depth of 30 metres). (TISSOT “Tissonic”)