This is a bearing kit by Avid RC for the Caster Fusion ZX-1.5R. We suggest that you use two of the 8x16 rubber seal bearings for the center diff because it isn't an enclosed area, this is why we have to selections for the 8x16 bearing. The bearings haven't changed through out their revisions.
ZX-1.5R Factory Pro
K8-T Factory Pro