This Hop-Up Option is for use with the XV-02 chassis. It is made of light weight and rigid 2mm thick carbon fiber and serves as a bumper support that ensures more secure attachment of urethane sponge and body mount. 2mm thickness carbon fiber bumper support x1 Rubber bushings x2 6mm snap pins x2 3x16mm round socket screws x2 Compatible with XV-02 chassis cars.