Hårdt presset

[Petersen]

""The Powermatic 80 is equipped with ETA’s newest movement, caliber C07.111, which is an evolution of the ETA 2824. At 80-hours, the power reserve is approximately twice as long as the 2824.

To achieve such an impressive power reserve, ETA engineers made of number of improvements. They were able to save energy by reducing the operating frequency from 4 to 3Hz (28,800 vph to 21,600 vph). Additionally, the use of a high-performance synthetic material (likely silicon) for the escapement also allows friction to be reduced, thus wasting less power. Furthermore, a reduction of the diameter of the barrel-arbor’s core made it possible to lengthen the mainspring, thereby allowing for an increased power reserve. ""