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Seiko 9S65

Probable

Grand Seiko's precision standard is its own and is not COSC certification; the two are frequently conflated in listings. The distinction matters when a specification claim is being checked against a dial or a certificate.

Specifications

Movement manufacturer
Seiko
Frequency
28,800 vph (4 Hz)
Jewels
35
Power reserve
72 hours
Winding
automatic
Complications
Centre seconds · Date

Architecture

Grand Seiko automatic with an in-house Spron mainspring and Seiko's own escapement components, regulated to Grand Seiko's internal standard rather than to COSC.

Related calibers

  • Related caliber

    Seiko 8L35

    Shares architecture; differs in finishing and in regulation standard.

References using this caliber

No catalog references are linked to this caliber yet.

Provenance of this record

Sources & Evidence

Secondary sourceAtlas & Crown research

Atlas & Crown — internal catalog research notes

Atlas & Crown

Accessed
2026-08-18

Cited for

This referenceProbable

Last verified: Not yet reviewed