I recently got a 6” clip on fan; when I went to clip it on my tent it would not hold. So I’m not sure what to call it, but I used the stuff people use in cabinets, in tool box drawers. I taped it to the inside of the clips works awesome.
Never tried it, but there is a thread around here somewhere with a fella that swore by a section of foam pipe insulation over the pole and then clip than fan over the insulation.