Kennedy: 21mm Wheel Nut Impact Socket 1/2" Square Drive Socket sizes: 17 and 19mm. Colour coded for easy identification. Can be used with retainer rings or pins. MPN: 21mm Wheel Nut Impact Socket 1/2" Square Drive Attributes: Bit Type: Hex Drive Size: 1/2in Drive Type: Square Finish/Coating: Black Oxide Material: Chrome Molybdenum Steel Number of Points: 6 Size System: Metric Socket Depth: Standard Socket Size: 21mm Socket Type: Impact Socket Standards Met: DIN 3129