The Triad Evo Slipper Clutch utilizes a new plate design that is self-centering and vented for less weight and cooling. The difference between these plates vs. our other Evo plates is that they fit on the larger topshafts that have 4mm flats (rounded part is 4.75mm). Currently, we know they fit on the Team Associated B6.1 line and the Yokomo YZ-2. Most likely these will fit other vehicles, so feel free to check and let us know.