Eterna-SONIC electronic

Swiss Watch Fair 970 BF 31
The new electronic movement with sonic resonator. From top the complete movement with built-in battery, the electronic module and the resonator. Vibrating at 300 cycles per second, the latter is specially poised with the aid of a compensation system in order to eliminate position errors. The complete watch is one of the many models presently in production. (ETERNA-SONIC electronic)