Futaba 54 mm servo arm with ball link. It weights 4 g. The high torque of modern digital servos meke's necessarie this type of servo arms. It's made in high density plastic with carbon fiber (nylon with 45% carbon fiber content) .The result of its manufactured is a high-strength component, which can be compared with Duralaluminium, but supports better the vibrations. It's manufactured in Germany using the latest CNC machines.