THETA Razor-C1 NFC HV Standard Brushless Cyclic servo (Black Edition)
High voltage, High-Torque, standard size brushless Tail servo.
Ideal for 520 all the way to 800+ class helicopters.
The Theta servos are at the top of their class due to their ability to be fully programmed via an Android NFC enabled smartphone. You can adjust things such as the center point, refresh rate, acceleration, as well as the PID control loop of the servo. You can make it feel however you want it to!