Work up to 6 times faster due to innovative drilling technology: Pilot hole drilled to a depth of 3/16 inch [5 mm] at 1,600 rpm, followed by disengagement of the pilot bit and automatic speed change to 520 rpm for optimal cutting speed for carbide annular cutter. The carbide annular cutter finishes drilling the desired hole diameter with minimum effort and specially developed annular cutter cutting geometry. Mechanical 2-speed gearbox with speeds from 0-1,600 rpm for efficient twist drilling and forward / reverse rotation for thread tapping up to 1/2 inch. Very safe operation due to the torque slip clutch. Protects the user when overloaded by separation of the driver and driven sides. Reversible FEIN high-performance motor with excellent speed stability. Electronic start, Variable electronic speed control. Speed-controlled tacho electronics. Torsion-free, barrel-type motor housing. Carbide core bits with optimized service life. Self-start lock. Torque slip clutch.