|Winding:||Automatic, Bi-Directional Automatic Winding|
|Diameter:||25.6 mm (11.5 ligne)|
|Complications:||Date, Day, Hacking Seconds, Leap Year, Month, Moon Phase, Quick Date Correction, Quick Day Correction, Quick Month Correction, Year|
|Hands:||Central Hour Hand, Central Minute Hand, Central Seconds Hand, Date Pointer at 12:00, Day Pointer at 3:00, Month Pointer at 9:00, Moon Phase Wheel at 9:00, Year Wheel at 9:00|
|Production: 1990 – 2000|
ETA’s 2891-9 is a modular perpetual calendar movement produced from 1990 to 2000. It is based on the ETA 2892-2, part of the second generation of the ETA 2890 family. The replacement, ETA 2891A9, based on the updated ETA 2892A2, was introduced in 1999.
The ETA 2891-9 paired a perpetual calendar and moon phase module with the ETA 2892-2 base. This increased thickness from 3.6 mm to 5.2 mm. Unlike the similar 2890-9, this movement has a central seconds hand.
The perpetual calendar layout is as follows:
- Central hour, minute, and seconds hands
- Day pointer at 3:00 (set by pusher at 1:30)
- Month pointer at 9:00 (set by pusher at 8:00)
- Moon phase wheel at 9:00 (set by pusher at 4:30)
- Year/leap year wheel at 9:00 (set with month pusher)
- Date pointer at 12:00 (set by pusher at 10:30)
Omega’s Cal. 1116 is a refinished variant of the ETA 2891-9.