brass synchros for Bullet and 2000E boxes, there are early and late versions
TTRGC610 – Bullet 1st/2nd Early Synchros
TTRGC611 – Bullet 3rd/4th Early Synchros. Width 9.8mm
TTRGC612 – Bullet 1st/2nd Late Synchros. Width 10.9mm
TTRGC613 – Bullet 3rd/4th Late Synchro. Width 10.8mm
Difference between the Early and Late synchros is the width per the picture.