Steel: 6140CrV 44-48 HRC Nickel-plated A: 19 mm B: 23.5 mm Length: 260 mm The hinged double-ended key is a non-demountable version of a drive and extension with a hinged twelve-point socket head (180° angle of inclination). It is designed for efficient use and transmission of significant force when working in hard-to-reach areas. Turning the socket head parallel to the key body allows for quick loosening and tightening of fasteners when applying high force is not required. You can also purchase a set of hinged keys.