Klein's Magnetic Color-Coded Hollow-Shaft Heavy-Duty Nut Driver features a fully pass through through drivers for driving nuts on threaded rod and prevents bottoming out. Rare-Earth metal magnet is protected by a brass inner sleeve and strike plate to prevent the magnet from falling out or being damaged by sharp edge threaded rod. Cold forged steel wrench assist provides greater torque. Color-coded handle and dome-stamped to easily identify the common 7/16-Inch hex size needed for the job