From Fender:
This chrome bridge assembly is for use on most American Professional and American Standard from 2008-present (fits most American Series models with a two-point synchronized tremolo), and combines modern two-point synchronized tremolo design with classic Fender® looks.
The new pop-in tremolo arm securely stays in position, no matter how hard you play. The arm tension can also be adjusted for a perfectly dialed-in feel that matches any player’s preference.