Yeah Racing Tamiya TT-02 Aluminum Essential Upgrade Set. This optional aluminum upgrade set is a great start in unleashing your chassis full potential. The Yeah Racing upgrade set equips the Tamiya TT-02 with aluminum front and rear lower arms, aluminum front knuckles, aluminum rear hubs and ball bearings. Perfect fit for the Tamiya TT-02. Increases durability and chassis efficiency. Components made from aluminum and anodized for a clean finish. (2) Aluminum Lower Front Arms. (2) Aluminum Lower Rear Arms. (2) Aluminum Rear Hubs. (1) Bearing Supported Steering Arm Set.