This is a 12-piece set of both ring and open end spanners. Each spanner has one open end and one box end of the same size. The elliptical shape ensures a firm and convenient grip. They are made of chrome vanadium with a satin finish. spanner sizes: 6 / 7 / 8 / 9 / 10 / 11 / 12 / 13 / 14 / 17 / 19 / 22 mm. They are in compliance with the din 3113 standards.