The El Primero was the standard for the entry level to mid range chronos for about 10 years. The high end chronos during that time mostly used the Lemania 2310, though some pieces used new old stock Valjoux calibres and others.
In the early 2000s, the El Primero was then replaced by a GP modular chrono movement, and then the Piguet 1185.
- SJX
The El Primero was used for the entry level chronograph, available in steel and gold. The El Primero is a good movement, but mid-range in terms of finishing and construction. It uses wire springs for instance. This was later replaced by the GP movement but available only in a gold case as DR stopped making steel watches in the early 2000s.
The Lemania was used for top end models, including a skeletonised version.
- SJX