This Schumacher Racing Products aluminum differential conversion is a factory replacement unit designed for the Cat PB 4x4 buggy platform. The set includes two metal differential assemblies, a larger housing unit and a smaller flange-mounted unit, replacing the standard differential components with machined aluminum construction. Designed as a direct-fit upgrade or replacement for the Cat PB drivetrain. Features: Machined aluminum construction Includes two differential assemblies Direct-fit replacement for Cat PB 4x4 drivetrain 7/7/26 cs