These 37mm swing shafts are used in the XV-02 chassis. Replace them periodically to ensure that your car runs at peak performance. Using with Item TAM54874 (TT-02 Adjustable Upper Arm Set) on the TT-02 chassis allows a wider range of camber angle adjustment. Compatible with TT-02 (use with Item TAM54623 and TAM51444) and XV-02 chassis cars.