Vibration-free. High torque at low, medium, and high speeds. Automatic SST(self-sending torque) overdrive system. Sealed, dust-free, and self-cooling design. Large LED display shows current status, information, and operating conditions.On-board microprocessor-controlled system. Built-in programmable Cruise Control feature. Sealed, long-life,micro-glide precision bearings. Ergonomic grip reduces fatigue.