Klein Tools 31676 1/2-Inch-20 to 5/8-Inch-18 Arbor Adapter Quickly converts 1/2-Inch-20 threaded arbors to 5/8-Inch-18 Hexagonal flange for easy removal For use with Klein arbor Cat. Nos.: 31650, 31655, 31660 Read and follow safety instructions in power tool owner's manual