Swiss Watch Fair 1971 BF 302
Here is the definitive version of the Longines quartz watch, which is expected to be on the market this summer. It is a “cybernetic” model with a quartz vibrating at 9,350 Hertz. Its energy consumption is low enough for the battery to have an 18-month energy reserve. Instant-change calendar with fast date adjustment mechanism with no moving of the hands (LONGINES “Ultraquartz”)