These bits are designed to deliver speedy and precise jobs for 3/8 drive impact wrenches. 9 pieces for each type of bits (Torx®, XZN®, and Hex) are carefully heat tempered to achieve Schrauben Schonenderes - more gentle on screw heads while retaining properties of strength, rigidity, wear resistance, corrosion resistance, and toughness of high-grade Chrome Molybdenum alloy. This set is perfect for tool trucks while a heavy-duty PE-HD blow mold case is also available.