These are bench dogs with a non-slip top. You can use them to hold the workpiece above the MFT table for sanding and finishing. They also work well for cutting. The shaft is 19.5 mm as they don't need a tight fit. I've cut a lot of sheet goods using my track saw and they raise the wood high enough that the saw blade will not score the work surface. For big sheets, I spread a dozen or so around the workbench for support. If the saw accidentally cuts one of the dogs no harm is done. I have included a picture of the 3M pads I bought which are 1.5" in diameter but any non-slip material could be used or perhaps circles printed in TPU. The peg is slightly smaller than 20mm but there are finger reliefs in the side to aid in removal. I have added a storage organizer that holds 36 of these. The hole is exactly 20 mm.