Like it says, just glued 5 pieces of .090 plexiglas together to get a big hunk of plastic. Drilled a real small hole in the center so I could use a compass to draw concentric circles on both sides. Laid out the small and large sizes on oposite sides and cut the small(approx. 80mm) hole with a jig saw. Then put some magic marker on the inside of the hole so I could see the outline better and used like a rotary rasp to cut the funnel shape to the large(92mm approx.) hole by hand with the plastic in a vice, working my way around and finished it with a sanding wheel. Cut the outside square and drilled the holes. Took a hour not counting the time it took the glue to dry.