The incredible speed and accuracy of the Spektrum H5020G gyro servo will transform the performance of any 250- to 500-size 3D helicopter. Besides delivering precise tail response and holding power that is second to none, it boasts a metal gear train designed to withstand the punishment of aggressive 3D maneuvers. It also has a specially designed case with an aluminum center section that dissipates heat so the motor and electronics run cooler and last longer.