Cal. 9164 is a tuning fork movement with day and date produced by Ebauches SA under license from Bulova. Based on the Bulova Accutron design and designed by Accutron designer Max Hetzel, Cal. 9164 was one of the ESA “Mosaba” family of movements and was included in the “Swissonic” line of electronic movements in the early 1970s.
Introduced in 1972, Cal. 9164 is closely related to the no-date Cal. 9160, released in 1968 but rarely seen, and date-only Cal. 9162, released in 1969. It was widely used by other Swiss companies and carried many brand names and calibre numbers:
- Baume & Mercier “Tronosonic” Cal. 19164
- Certina “Certronic” Cal. 29-152
- Eterna “Eterna Sonic” Cal. 1551
- IWC Cal. 160
- Longines “Ultronic” Cal. 633.2
- Omega “Speedsonic” Cal. 1260
- Titus Tuning Fork
- Tissot “Tissonic” Cal. 2020
- Zenith Movado Cal. 50.5