[This part is useful for improving the performance and setting of RC cars]
The aluminum machined differential joint cup is treated with a highly lubricating anodizing to reduce the weight of the drive system and achieve smooth movement. It can be used as a spare for the TT-02 TYPE-SRX. and can also be used as a lightweight. highly lubricating replacement part for the differential joint when installing the OP.2049 XV-02/TT-02 oil-filled gear differential (39T) unit on the TT-02 chassis. A set of four plastic swing shaft caps to prevent wear on the joint cup and drive shaft is also included.

[Basic specifications]
Made of aluminum with a highly lubricating anodizing treatment

[Manufacturer page]
https://www.tamiya.com/japan/products/22065/index.html