The 85191 is a rugged conduit-fitting and reaming screwdriver designed for professional use. Its hooded-blade design features a 5/16" tip and is built to prevent slipping out of screws, particularly when tightening hard-to-reach conduit fittings. The tool simultaneously reams and smooths the inside and outside of 1/2", 3/4", and 1" thin-wall conduit ends to protect wires from damage. A longer Cushion-Grip handle provides enhanced comfort and greater torque for reaming applications, and the reaming blade is replaceable. This screwdriver is an ideal all-in-one tool for electricians working with conduit.