Paraflex is the name of Rolex’s proprietary anti-shock system for their automatic watch movements. In technical terms, it is a spring-loaded mounting system for the jewel bearings that support the balance wheel. Anti-shock devices help protect the balance wheel’s pivots from damage in the event of dropping the watch or hitting it against something hard.
Rolex registered the trademark for “Paraflex” on March 5, 2008 (although below you will see that they developed and patented it in 2005).
You can identify Parashock by the diagonally positioned rectangular oval shape with two lines coming from each end.
List of Rolex Calibers with Paraflex:
The following calibers are equipped with Paraflex. If there is a movement with Paraflex not on the list, please add it in the comments below.