Especially adaptable for delicate work the revolving heads are concave and hexagonal for sensitive control blades are hardened and tempered overall length of screwdrivers are approximately 95 mm 3 34 inch set of seven in case 06mm 0025 inch 1mm 0040 inch 14mm 0055 inch 18mm 0070 inch 2 mm0080 inch 25mm 0100 inch and phillips no 0