Having the right tool for the job is critical and technicians working in cramped spaces understand better than anyone the power of this simple statement. This wide range is the backbone that gives GEARWRENCH its reputation for unprecedented speed, strength and access. The result is increased productivity for those who keep GEARWRENCH tools in their box. Made from chrome molybdenum alloy steel (cr-mo) for exceptional strength and durability Off-corner loading design for reduced fastener rounding Manganese Phosphate Coating for Corrosion Resistance Parallel Neck Down Design On 3/8", 7/16" 1/2" and 9/16" Sizes for Improved Access to Restricted Fasteners High-Visibility Laser Etched Markings for Quick Size Identification Secondary Hard Stamping Includes Blow Mold Case With Reinforced Steel Hinges and Steel Buckles for Strength and Security.