The DS-3688HB is a great high-performance, fast actuator for small mechanisms. Digital electronics combined with a coreless motor and two ball bearings give this servo a distinct edge over similarly sized servos. The 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).
You can find more information about this servo under the specifications tab and in its datasheet (134k pdf).
Note that as with most standard servos, stalling this servo can strip its gears.
Note: This servo is also sometimes labeled as “HD-3688HB”.