Steel: 6140CrV 44-48 HRC Nickel-plating A: 18 mm B: 19 mm Length: 225 mm The double-sided hinged key is a non-disassembling version of a drive and extension with a hinged twelve-point socket head (180° tilt angle). It is designed for efficient use and transmission of significant force when working in hard-to-reach areas. Rotating the socket head parallel to the body of the key allows for quick loosening and tightening of fasteners when no excessive force is required. You can also purchase a set of hinged keys.