Rolex 4130

Rolex's first in-house chronograph movement, released in 2000 for the Cosmograph Daytona. Replaced the Zenith-based 4030 caliber. Features column wheel and vertical clutch for instantaneous chronograph start. Architecture uses far fewer components than standard chronographs, enhancing reliability. First Rolex movement to use ceramic ball bearings in the automatic winding system for better efficiency and lower maintenance. Replaced by caliber 4131 in 2023.