This is an "S" knife, with a support disc. It is an adjustable slicer plate that can fit Uniworld Persada’s #12 and #22 size hub. It will fit Hobart slicing attachments and Uniworld's UVS-9SN or 922SN. For a perfect fit measure the square in the back of the slicer attachment. A standard #12 hub has a 1/2" square, while a standard #22 hub has a 3/4" square. It is Perfect for slicing cabbage, carrots, cucumbers, etc.