Longines Ultronic with Longines 6132 (Esa 9162) electromechanical calibre with 12 jewels in very good condition and working perfectly. Unlike modern mechanical or quartz watches, the movement of the seconds hand is completely fluid and continuous, and does not have a jerky effect. They are part of the history of watchmaking. The move from mechanical to quartz. Max Hetzel developed the concept of the tuning fork after joining Bulova in 1950. It was the Accutron, which used electromagnets that act on a tuning fork vibrating at 360 oscillations per second (Hz), much faster than the balance wheel found in a mechanical watch (2.5–5.5 Hz), which increased precision. ESA licensed the Accutron technology in 1968 and almost immediately began production of their version of the Bulova design. The central component was called Mosaba, from 'Montres Sans Balancier'. It measures 35 mm, excluding the crown. A beautiful blue dial with the Longines and Ultronic T - Swiss Made - T symbols Crown signed Longines Screw-down case back with the inscription 16 322419 Stainless Steel. Black leather strap. A new battery has been installed. Sent in an original Longines luxury case by registered and insured mail.