Pistons (et al)
FYI most OEMS source items like pistons and contract with specific specialty manufacturers accordingly.
With EU brands it is usually easy,even on the OEM packaging to see and find out which contracted manufacturer the OEM uses or used in regard to powerplant components as well as chassis and controls components. They seem to advert and promote the specialty brands they use, even chassis houses like when Verlicchi was a major player with Ducati and others.
Asso Werke (big one, that most have never heard of), Athena and Woessner are examples of 3 of many manufacturers used by various EU OEMs at various times.
The Japanese OEMs tend to be quieter about their labeled OEM parts as far as outside contracted mfgrs go. But you do see them open about many items like electronic stuff, FI, wheels, suspension, carbs etc.