The height was increased by 3/4" (19mm) to allow more room for your hand when tightening the rear knob or adjusting the altitude. We also eliminated the sharp corner to prevent the possibility of the cords catching. It looks a bit spiffier as well.
All 1200 mount models (DA, QMD, SMD and GTO) that have been produced.
This Tall Polar Fork Assembly was included on all later 1200GTO mounts.
Upgrade Replacement of 1200GTO Polar Forks S1200PF-B (PDF file). These instructions show the 1200GTO, however are applicable to all models.