LONG SERVICE LIFE - 45# high impact steel sockets can withstand higher torque from impact tools and ensure long service life. Premium black oxide finish provides maximum protection against rust and corrosion. Enhanced Stability Design - 6-point Allen recessed design grips the flat sides of the fastener, not just the corners, preventing collapse when used with wrench impact and power fasteners under high torque and hammer stress. Rounded corners are degraded. VISIBLE SIZE CODE - All 1/2 drive deep impact sockets are etched with size markings for quick identification of gauge and drive socket size. File Case - Includes a sturdy plastic storage case for easy organization and storage of drive cases and for easy portability of the case. Most Common Sizes Included - Set includes 1/2 (Metric) high torque impact sockets: 10mm, 12mm, 13mm, 14mm, 15mm, 17mm, 19mm, 21mm, 22mm, 24mm Specification: Black Square Socket Size: 1/2 (78mm) Hex Socket Size (Metric): 10mm, 12mm, 13mm, 14mm, 15mm, 17mm,