Heat treated and hardened with a fully polished mirror finish. Chrome Vanadium steel 3/8"Sq Drive x 12-Point WallDrive® rings. Minimum/maximum length: 65/70mm. Ideal for use with torque wrenches (please note: a setting adjustment is required to compensate for the increased length of leverage when using these torque adaptors). Suitable for limited access applications. Supplied in an EVA storage tray.