Bosch HTH181-01 18-Volt Lithium-Ion 1/2-Inch Square Drive Impact Wrench Kit with 2 Batteries, Charger and Case - Detent Pin 500 ft lbs of max torque - Fast tightening/removing of heavy duty fastners (lag screws, concrete anchors, lug nuts) 6.7 lbs and 10" in Length - Most lightweight design with short head length for least amount of user fatigue. Spring-Loaded Hammer and Anvil - High Amounts of torque with little torque reaction 1,900 RPM with 2,100 IMP - Optimized mechanism creates added efficiency FPS and ECP - Works with Slimpacks, or Fatpacks, monitors battery to reach maximum life.