Premium CR-MOMade of premium impact grade chrome molybdenum steel construction with black phosphate finish. Set Includes10-piece 3/8" Drive Deep Universal Impact Socket SetMetric): 10mm 11mm 12mm 13mm 14mm 15mm 16mm 17mm 18mm 19mm. VersatileFlexible socket design allows a full 360° of freedom for the universal head to angle and rotate, to reach tight spaces for more better coverage. Laser Marking High-contrast size marking is permanently laser etched and easy to read, even in low light. Service GuaranteeAll MIXPOWER Tools meet or exceed ANSI performance standards. It comes with 1 year quality guarantee.