Freud dado blade. Some called it the wobble blade. Adjustable wobble to cut varying width dado's. New in box, and never mounted. 10" blade and 1" arbor. The arbor depth is a tad over 1.5" so you would need a saw with an extended shaft I suppose. No need for shims to get the right width and shims usually never got it right to begin with. These things are a work of art! $50 email only through cl relay. I don't see yours and you don't see mine.