The 8312TG is a premium standard-size servo from Power HD that offers a great combination of torque and speed. It has a coreless motor with an all-metal (titanium-shielded aluminum) gear train, digital control electronics, and two ball bearings on the output shaft. Servo horns and associated hardware are included.
The HD-8312TG is a premium standard-size servo with plenty of torque and speed. Digital electronics combined with a coreless motor, titanium-shielded aluminum gears, and two ball bearings give this servo a distinct edge over typical standard-size servos. The 8312TG works with standard RC servo pulses at frequencies up to 333 Hz. The 12″ (300 mm) lead is terminated with a standard “JR”-style connector, which is Futaba-compatible. The picture below shows an example of the hardware that might be included with this servo (hardware might vary).
The picture below shows the all-metal, titanium-shielded aluminum gear train and ball bearings that help the servo deliver such high torque.
You can find more information about this servo under the specifications tab and in its datasheet (380k pdf).
Note that, as with most hobby servos, stalling or back-driving this servo can strip its gears.