- Seiko 4206B
- automatic
- sweep second
- day: quickset, 2 languages
- date: quickset
- 7.75”’
- Dm= 17.20mm
- H= 5.50mm
- 17 jewels
- f = 21600 A/h
- family/generations:
- balance bridge:
- Seiko 4205A: date, 17 jewels
- Seiko 4206A: day, date, 17 jewels
- balance cock:
- Seiko 4205B: date, 17 jewels
- Seiko 4206B: day, date, 17 jewels
- Seiko 4206B: day, date, 21 jewels