Manufactured from premium impact grade Chrome Molybdenum steel, construction with corrosion-resistant black phosphate finish for durability. Set Include: 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm. Magnets keeps the fastener in the socket better. Radius corner design, reduces wear and increases torque on fasteners by placing force on fastener walls rather than fastener corners. Permanent high visibility laser etched size marking on each socket for quick size selection when working. Meets or exceeds ANSI performance standards. It comes with 1 year quality warranty. Manufactured from premium impact grade Chrome Molybdenum steel, construction with corrosion-resistant black phosphate finish for durability. Radius corner design, reduces wear and increases torque on fasteners by placing force on fastener walls rather than fastener corners. Permanent high visibility laser etched size marking on each socket for quick size selection when working. Meets or exceeds ANSI performance standards. It comes with 1 year quality warranty.