The Conduit Locknut and Reaming Pliers Tighten Up to 3/4-Inch Emt and 1/2-Inch Rigid Locknuts. The Special Jaw Is Designed For Locknuts, Conduit and Caps. Serrated Jaws Deburr The Outside While The Nose Reams and Smooths The Inside Of Conduit Up to 3/4-Inch Emt. The Long-Nose Design Makes It Easier to Reach Into Electrical Boxes.