1" Air Impact Wrench, Super Duty, 750 ft-lb Torque, Thru-hole Retainer, D-Handle Inside Trigger. The twin hammer impact mechanism ensures this series is reliable, durable, and will produce the same output every time. Durability: This Series features an iron hammer case and metal housing that’ll withstand harsh conditions and drops. Reliability: Resistant to fluctuations in air pressures, this series will work just as well in any condition. Comes with a 1-year warranty. Great for Outdoor Environments: This wrench contains a bronze end-plate that increases durability and is corrosion resistant.