I was considering putting a .99 cent filter in front to try and catch the first wave of dust and make the MFG fitted ones last longer.Those things do work well as long as you keep the filters clean. You will be amazed how quick they get dirty.
It is a little smaller. 10" x 17"If the Wen unit uses a 12" X 24" filter (same size the Jet air filter uses) you can get them at Home Depot or Lowes. I think the filter might be cheaper there than buying the Wen manufactured ones.