ISO 691, ISO 7738, ISO 3318, ISO 1711-1 and DIN 3113, material: high-performance steel alloy, U-shaped shaft ensures greater comfort, 15 ° jaw position with thin head for improved accessibility, double hexagon with dynamic drive profile ensures for longer life of screws and nuts, ring side angled 15 °, larger size markings on both sides for easy identification, chrome-plated micro-matt design with high-quality surface, patented U-shape