Happy Holidays! Everyone.
I've been searching the web to find out which grade of ETA 2824-2 is used in Sinn watches, especially in 556/656 models. But, I haven't found any definitive answer to this. Only thing that seems to be agreed in general is that Sinn does not use COSC-level 2824.
I guess someone must have gotten an official answer from Sinn directly. or Do watch companies usually not reveal this type of information?