This is an optioinal Avid RC Triad B44.2 Spacer. The Avid Triad B44.2 Spacer allows users to replace the standard VTS slipper and use the AVID Triad "Mod" Clutch. The Triad Clutch calms the car down and delivers a smoother throttle feel than the stock setup. The 44.2 bulkheads are shifted 6mm farther apart than on the 44.1, so this spacer goes behind the Triad slipper to compensate for the longer slipper shaft.