This aluminum servo horn for the Tamiya Hi-Torque Servo Saver (item 51000 and 50473) is specifically designed for use on the RM- 01 chassis. It increases the strength of the steering section to enable a more direct steering feel. Specs & Features Aluminum Horn x 1pc. Use with Item 50473 Hi-Torque Servo Saver or Item 51000 Hi-Torque Servo Saver (Black). Compatible with RM-01 chassis.