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Omega 1120

Probable

The movement in the Seamaster Diver 300M of the 1990s, including the reference that made the model famous. Calling it an ETA is accurate and is not a criticism: the 2892-A2 is among the most reliable automatics ever industrialised, and Omega's contribution was finishing, adjustment and chronometer certification rather than architecture. The identification matters because it fixes what the movement should LOOK like — a 2892 bridge layout and rotor, decorated to Omega's specification and signed by Omega, not an Omega-designed architecture.

Specifications

Movement manufacturer
Omega
Base caliber
ETA 2892-A2
Production
1993–2007
Frequency
28,800 vph (4 Hz)
Jewels
23
Power reserve
44 hours
Winding
automatic
Complications
Centre seconds · Date
Certification
COSC chronometer

Architecture

ETA 2892-A2 finished, adjusted and chronometer-certified by Omega. Automatic, centre seconds, quickset date, 21 jewels in Omega's execution.

Service practice

Because the base is a mass-produced ETA, generic 2892 service parts fit. A 1120 rebuilt with undecorated generic components will run correctly and will not look right; the difference is an originality finding rather than an authenticity one, and should be reported as such.

Related calibers

References using this caliber

Provenance of this record

Sources & Evidence

Primary sourceManufacturer archive

OMEGA Vintage Database

OMEGA SA

Accessed
2026-08-18

Cited for

This referenceProbable
View source
Secondary sourceCollector research

Ranfft Watch Movement Archive

Dr. Roland Ranfft (archived and maintained by volunteers)

Accessed
2026-08-18

Cited for

This referenceProbable
View source
Primary sourceTechnical documentation

COSC — Contrôle Officiel Suisse des Chronomètres: testing criteria

COSC

Accessed
2026-08-18

Cited for

This referenceHigh confidence
View source

Last verified: Not yet reviewed