Futaba BLS251 Digital Brushless Heli Rudder Servo 3.8kg/.06sec/61g
Futaba BLS251 S9254 Digital Heli Rudder Servo is designed specifically for helicopter rudder operation. This hyper fast digital servo is ideal for tail rotor control on helicopters as well as many other applications requiring the ultimate in speed of response, yet still requiring good torque. This servo features a Brushless motor that lasts longer and operates at a lower temperature than a brushed motor with 30% faster response times, smoother operation and a dual bearing gear train. Compatible with Super Narrow Pulse (760µs) drive.
Specifications: Torque(4.8V): 3.8kg.cm Speed(4.8V): 0.06sec Torque(6.0V): NA Speed(6.0V): NA Dimension(mm): 40x36x20mm Weight(g): 61g
If you fly a 2000$ heli, than this (superreliable and fast servo), is worth every dollar. This is not a bling bling part, it serves his function with excellence. I have 3 Trex 700's, and they all have this Rudder servo.