ETA SA 2851

The ETA caliber 2851 is a manual-winding mechanical movement manufactured by ETA SA in Switzerland. It operates at a frequency of 21,600 vph with 17 jewels and Incabloc shock protection. This time-only movement is a true no-date caliber and an early member of the ETA 28XX Gabarit movement family, representing a lower-beat-rate variant of the caliber 2850. Documentation first appears from 1976.