Built from the highest quality materials. Made of special tool steel, with excellent resistance to degradation as a result of intensive and continuous use. Composed of: 1/2" heads with diameter: 9-10-11-12-13-14-15-16-17-18 -19-20-21-22-23-24-27-30-32-34 mm and 2 1/2 "extensions. Rubber handle, absorbs the strain even in the most demanding jobs. Ideal for professionals in the field of mechanical repair and assembly.