| Manufacturer | Seiko Time Corp. |
| Caliber Number | 4N30, 4N30A, 4N30B, 4N30C |
| In-House? | Yes |
| Movement Type | Quartz, battery-powered |
| Lignes | 4.75”’ x 6.5”’ |
| Diameter | 10.8mm x 14.5mm |
| Height | 3.25mm |
| Jewel Count | No jewels (0) |
| Frequency | 32,768 Hz |
| Accuracy Rating | +/- 15 seconds/month |
| Battery Cell # | 379 / SR521SW (Silver oxide, 1.55 V) |
| Battery Life | 2 years (unconfirmed) |
| Hand Count | 2 |
| Hand Sizes | .90mm / .45mm |
| Functions | Central hours; central minutes |
| Hacking Seconds? | Yes |
| Country of Manufacture | Made in Japan |
| Known Models | Seiko Essentials Collection (Mens Refs: SWR049, SWR052, SWR064 / Ladies Refs: SWR044, SWR046, SWR048, SWR053, SWR054, SWR066, SWR078, SWR083, SWR085, SWR091, SWR093) (Add your watch to the comments below…) |
The Seiko caliber 4N30 is a small, minimalist, time-only, 2-hander quartz movement with zero jewels.
This caliber is part of the 4N family of rectangular movements with zero jewels. This series of movements includes the 4N00, 4N01, 4N20, 4N21, 4N70, 4N71.
Examples of watches with the 4N30:
The cal. 4N30 is typically found in Seiko’s “Tank” shape watches, and is used to power both men’s and women’s models.
Additional Resources:
network of watch sites
Recent Comments
Certina DS-8 Chronometer PN:C033.451.11.031.00
Henry Archer Akva & Zelos Aurora using this caliber
Supposedly, hand winding is bad for ETA 2892 and 2824 clone calibres, but I read…
à mon avis, elle date à peu près en 1965
Interesting, what model is that seiko? I couldn't find it
I take it, this is the analogue version of the NN50 which is the all…
The new launched (2025-01-22) Panzera Aquamarine M45 chronograph