This expansion bit is designed for easy, accurate adjustment. The two movable tool-steel cutters are graduated in 16ths. One cutter is used to drill holes from 5/8" to 1 1/8"; the other cutter adjusts from 1" to 1 3/4".
Also useful when you need to drill a hole of an uncommon or in-between size. The long screw point provides ample pulling power to draw the cutter smoothly into the wood.
6 5/8" overall; nominal 3/8" hex shank. Made in Japan.