Features: One-handed operation, compact size, lightweight and portable, comfortable to grip. Quenched and hardened spindle, the raw-material is hardened by quenching process, which can withstand higher torque, the max torque is 1280N.m/128kg. Nickel-molybdenum alloy material pin, wear-resistance and with fine durability. Tungsten steel metal rotor, high power conversion efficiency, which can work continuously for more than 10 hours. Double-hammer thumping structure, 3 speeds adjustable, forward and reverse adjustable, practical and useful. It is widely used in lots of industries, such as automobile repairing, heavy equipment maintenance, product assembly, major construction projects, installation of wire thread inserts, and other places where high torque output needs.