I have two of these, one for zero clearance of my Forrest WW II blade, the other for my stacked dado set. It takes just a couple of minutes to adjust the screws to get a perfect fit. Then it's a simple matter of clamping a scrap 2X4 or something onto the top of your table saw, covering the insert, and run the blade up through the insert to your desired height. On my zero clearance insert for the Forrest I went up as high as the saw would go, on the dado insert I went up a full two inches. It was easy to drill out the insert to allow for my splitter.