Omega Caliber 1120

The Omega caliber 1120 is an automatic movement found in some Omega Seamaster Pro 300M watches from the mid 1990s (1996?). Technical documentation was found dated May 1995.

This movement can be found in both the full-size 41mm and the mid-size 36mm SMP models.

The 1120 is essentially based on the ETA caliber 2892-A2 framework. It has 21 jewels with a beat rate of 28,800 bph, 4Hz.

A note about power reserve: Earlier 1120 documentation stated 42 hours for the 1120, but listings currently on Omega’s website say 44 hours. The ETA 2892A2 which the 1120 is based on has a 42 hour power reserve. It’s safe to say expected power reserve can be somewhere between 42-44 hours.

This movement has a quickset date, hacking seconds, and can be hand-wound.

1109 to 1120:

The cal. 1120 replaced the Omega caliber 1109. That is why some models will have the older 1109 and other will be powered by the 1120. For example, the 2551.80.00 midsize SMP is listed by Omega as having the 1120 here, and the 1109 here.

Omega 1120 VS 1120A:

There is a similar calibre 1120 A with some of the following differences as detailed by official tech sheets: