Set includes 5 pieces: 8, 10, 13, 17 and 19 mm.Metric sizes.Patented U-shaped design.Open end angle 15° with a slimmer head for improved accessibility.Larger and bi-directional size marking for easy identification.12-point Dynamic-Drive™ profile provides longer life for screws and nuts.Chrome plated micro-matte finishing provides high quality surface.High-performance alloy steel.Standards: ISO 691, ISO 7738, ISO 3318, ISO 1711-1 and DIN 3113.Available in plastic holder