These Schumacher Racing Products aluminum differential inserts are a factory replacement for the Cat PB 4x4 buggy platform. Sold as a pair, they fit into the differential assembly as part of the drivetrain. The metal construction offers a durable alternative to stock plastic components in this position. Features: Aluminum construction Sold as a pair Fits Cat PB 4x4 drivetrain Direct factory replacement fitment 7/7/26 cs