I make them. I have six sets so far. Mostly 3". The pipe is 6" (from memory, if you want I will measure on monday when I go to the shop, same width as the isolater though, touch bigger)with a 2" hole cut in a 3/16" thick plate welded to the top. Cut the tubing to whatever height you need the cut a piece of plate to 6x6 drill your 2" hole, I use a bimetal hole saw, then weld it on to the tube and cut with torches, or plasma, around the weld. Presto you have one spacer. Add pink paint(only kidding).