This sale is for a Eterna Sonic Kontiki F300Hz Watch , Vintage 1970s . V RARE
High grade watch and cutting edge technology of its time. Based around Bullova's Accutron system of using a tuning fork that is vibrated by electro magnets and the vibrations are used as a power source for the watch mechanical parts. The movement is a Mosaba ESA 9162 which is also used by IWC, Omega, Eternal, Tasso, Zenith, Certina, Baume and Rado as well as others. Circa 1969 to 1976. 
Very expensive in the 70s when new and quartz was in its infancy . Made in low numbers and very rare to find one of these for sale . A real classic and iconic 1970s Swiss watch , the Kontiki was the equivalent of Omegas Seamaster , thus it was a divers watch with screw down crown . I could not guarantee water proof now though due to age . This is a thick and heavy watch , seriously collectible. In nice condition and all original . These are getting hard to find and going up in value .
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Condition - Great used condition and well looked after , please see all pictures . Some bubbling or patination to the dial which does not detract and is part of the watches history . Perfect working order , new battery fitted prior to posting . No guarantee for waterproof .
Age / Circa - Made in Switzerland , Circa 1970s .
Movement - Swiss quartz Mosaba ESA 9162 tuning fork movement . 
Dial - Silver dial with chrome hour batons and hands . Quick set date window at 3 . There is bubbling to the dial . Please check all pictures .
Crystal - Original glass crystal , no scratches .
Case - Octagonal , angular shaped case , all in stainless steel , Polished and brushed finishes with screw back cover .
Case Size - 44mm top to bottom 36mm side to side ( without crown ) and 12.2mm depth
Bracelet - Original , very heavy and thick bracelet . These were also fitted on some other top Swiss brands . Stainless steel from solid links . Fits max 7 3/4" wrist .