This is an Xray composite gear differential cover in the large volume size, molded from a graphite-composite mixture for the XB4 and XT4 platforms. The graphite composite construction is designed to offer improved durability, higher temperature resistance, and greater wear resistance compared to standard composite. This set includes both the diff cover and the diff case, giving you everything needed to replace or upgrade the outer differential housing. It is a factory Xray replacement part built to original specifications. Features: Graphite composite mixture for increased durability and wear resistance Higher temperature resistance vs standard composite Large volume case design Includes both diff cover and diff case Lightweight construction 7/7/26 cs