The Milwaukee Hand Tools HOLLOWCORE™ Magnetic Nut Driver features a thread-thru design for unlimited depth in threaded rod and long bolt applications. The magnetic universal driver heads fit 4 x more fasteners including: Square, Hex, 12-point and Spline. Removes rusted and stripped bolts. Can attach a wrench to the hex shank to provide additional force. Designed for maximum durability, the Wrench Ready hex steel shanks are forged and chrome plated. Milwaukee Nut Drivers are designed for the job site.