This is a completely custom design that I put together in an attempt to solve the issue of dust collection at the miter saw. I designed the pieces specifically to work with my Bosch GCM12SD, however I believe it is possible to rearrange the pieces, potentially with some alterations, to make them fit other saw models. This would require some R&D on your part!
More than likely you found these plans via my YouTube video documenting my build process. If by chance you haven’t seen it, make sure you check it out for a very detailed look at how to assemble one yourself. Watch YouTube Video