This is the Exedy Pilot Bearing for those of you who need a replacement. Although small as a component, the pilot bearing is an important part of your clutch assembly. The pilot bearing sits dead center and inside of the flywheel on the engine block. When re-installing the transmission, the edge of the input shaft goes into the pilot bearing allowing the input shaft to spin freely. If your input shaft is worn or damaged, then it could cause strain to your transmission, or your input shaft will not spin at all. Therefore, don't skip on the pilot bearing the next time you do a clutch job. Get yourself a quality example from Exedy.