SK Hand Tools 46119 1/2-Inch Drive 19-Millimeter and 21-Millimeter Metric Flip Socket 1/2-inch drive 19mm and 21mm metric flip sockets specifically made for automotive applications Black coating retains more rust preventative compound than black oxide Provides increased strength; avoids rounding of rusted or damaged fasteners SureGrip hex design that drives the side of the hex 1.19-inch diameter; 2.75-inch length