This is the HS-5245MG Metal-Geared, Ball Bearing, Hi-Torque Digital Servo from Hitec. The HS-5245MG is latest addition to Hitec's ever evolving digital servo line. With a custom designed programmable digital circuit and our unique Alumite gear train technology the the HS-5245MG is ideal for applications that call for a small lightweight, high speed, high torque servo. By utilizing the standard size Hitec spline, any horn or arm that fits on a standard Hitec servo will fit on the HS-5245MG.