Heat treated CR-440 steel for strength and durability</br>DirectTorque Technology helps prevent rounding of fasteners</br>Laser etched markings for easier identification on black phosphate finishes</br>O-ring and retaining pin compatible for added job-site safety</br>Oil rubbed Black oxide coating for corrosion resistance</br></br>Product Description</br></br>Heat treated CR-440 steel, DirectTorque Technology, Laser etched markings, O-ring and retaining pin compatible, Black oxide coating.</br><br/>http://www.amazon.com/gp/product/B01N0NP5TV