10.5”’, Dm= 23.3mm, Do= 23.7mm
f = 21600 A/h
power reserve 40h
Balance staff U3307
1.30 x 0.70mm
micrometer regulator, Kif-Ultraflex:
standard regulator, Kif-Flector:
In the 1970s, Longines resisted manufacturing quartz watch movements and instead developed ultra-thin mechanical movements. These thin movements bridged the gap until Longines joined the Societe Suisse de Microelectronique et d’Horlogerie (SMH) in 1983 — the conglomerate that would continue to evolve into the Swatch Group.