ETA Caliber 2892A2

Aware of the issues, ETA chose not to retire the 2892-2 altogether (this would happen in 2000), yet sought to create a better version to co-exist, resulting in a revised cal. 2892A2 – with improved winding efficiency via the modified rotor – by reducing the chamfer around the circumference of the oscillating weight to add mass at the edge. Also, ETA engineers switched from a stud to support the intermediate reduction wheel to a jewel on the upper winding bridge, which resulted in less winding friction due to the intermediate reduction wheel’s much better stability. Notably, the official jewel count remained at 21, yet with the updated cal. In 2892A2, attaining full power reserve became much easier than before, and it also featured the finishing and decoration that was superior to 2892-2, even in basic models.

11 1/2 ”’
Diameter 25,60 mm
Height 3,60 mm

Hours, minutes, central second
Date display in window, semi-instantaneous

Quick correction of date
Time setting with stop-second
Self-winding mechanism, bidirectional

Frequency: 28’800 vibrations per hour; 4 Hz
21 jewels
Regulator system ETACHRON
Typical power reserve: 50 hours