Steel: 6140CrV 44-48 HRC Nickel plating A: 20 mm B: 21 mm Length: 255 mm The hinged double-sided key is a non-dismantling version of a drive and extender with a hinged twelve-sided head (angle of inclination 180°). It is designed for efficient use and transmission of significant force when working in hard-to-reach places. The rotation of the head parallel to the body of the key allows for quick loosening and tightening of fasteners when a large force is not required. You can also purchase a set of hinged keys.