HPI Racing 102777 Sf50 Servo Metal Gear, 12kg-cm/6.0V This high torque SF-50 Servo is a direct replacement for the SF-5 servo found on HPI trucks and buggies High torque and a tough metal output gear give it the strength needed for applications like the steering of the Savage XL, Savage Flux and Vorza Flux If you're looking for more torque, the SF-50 is an easy bolt-in upgrade for the HPI SF-1, SF-10, SF-2, SF-20 servos