RB601 is a high quality, direct-fit release bearing that meets or exceeds OE standards.
PB1004 is a high quality replacement bushing or bearing that is placed in the end of the crankshaft or in the center of the flywheel, depending on the vehicle. It is used to support the end of the transmission input shaft.
AT90 is an alignment tool that facilitates the installation of an ACT pressure plate by correctly aligning the clutch disc with the pilot bearing. This results in easy alignment with the transmission input shaft.