King Seiko Chronometer 4420-9990
Why it matters
The essential bridge in my reading of the story. The lugs broaden towards the case and their outer lines almost absorb the circular body into a common outline.
What I look at
The flatter, outward-flaring bezel reinforces the directness of the dial and hands.
The watch
| Reference shown | 4420-9990 |
|---|---|
| Earlier Chronometer | 49999 |
| 4420-9990 production | January 1965–December 1966 |
| My example | August 1965 |
| Movement | 4420A · manual wind |
| Jewels | 27 |
| Frequency | 18,000 vibrations per hour |
| Seconds setting | Hacking |
| Movement height | 4.00 mm maximum |
| Case width | ≈ 36.6 mm, excluding crown |
Case width is approximate. The 0.1 mm difference from my KSK is below the confidence of these measurements.
Related forms
The 57GS 5722-9990 is a revealing formal neighbour, while the steel 44GS carries the integration of lugs and case further. A shared manufacturing origin with the 57GS remains a hypothesis.