Of course it is in-house like any other Lange watch. Of course some specific parts could have been developped with some external providers but why do you have such question in mind? Fx
...because I don't know. I know the Datograph part is all inhouse, but I don't know if the perpetual part is 100 per cent inhouse. May I ask why it is so wrong to ask this question?
The PC module was designed in-house and is exclusive to Lange. But I never feel comfortable with this kind of question since I don't know what in-house exactly means. Do we know if a specific department of another brand from Richemont was involved or not ...