PETOL FLANGE ALIGNING TOOLS are a safe, fast, and effective solution for even the toughest flange alignment jobs. The tool’s tapered shaft is a feature that eliminates the need for hammering and prying when lining up flange bolt holes. PETOL Flange Aligning Tools are made of steel and black oxide coated for rust protection and marked with both the bolt hole size and part number for easy identification. Specifications: Bolt Hole Size: 3/8" Length: 2-1/8" Weight: 3/4 oz. How it works: Simply find a bolt hole that is aligned enough for the tapered shaft to fit through and turn. Turn until the bolt holes are in alignment. If necessary, use a second tool and turn until the bolt holes are in alignment and insert flange bolts.