ESD safe. Brushless motor offers high performance and low maintenance, eliminates carbon dust for cleaner operation and provides longer tool life. Internal torque adjustment. All magnetic switches for long life and low maintenance. All metal gears. 4 mm drive model offers greatest flexibility for small fasteners or vacuum pick-up applications. 4 mm drive is a HIOS drive (wing style). Screwdriver is switchable lever start or push-to-start.