Amana Tool 46272 Solid Carbide Foam Cutting Up-Cut Spiral 1/4" D x 2-1/4" cut height x 1/4 shank x 4 Inch Long Flat Bottom Router BitThis is an UP-Cutting Bit, what is the difference? - A down cutting bit is used for cutting out tool pockets, or just general cutting of foam with the face/finish side up. - An Up cutting bit is used when you are cutting with the face side down and are doing perimeter shaping.