This is the ST Racing CNC Machined Aluminum Solid One-Piece Heavy Duty Servo Mounting Bracket/Chassis Brace for the Traxxas TRX-4. This Mounting Bracket will greatly reduce the flex in the servo mounting area and transfer more steering power to the steering linkages (instead of being lost in the twist of the flex) and also double as a strong chassis brace for the front end of your TRX-4.