Dolphin Maytronics 9991432-R4 Ultra Fine Cartridge Filters Set of 4 Fits the following pool cleaners ONLY: Supreme M4, M5, M200, M400, M500, Liberty, Wave 65, Wave 90, C4, C5, Oasis Z5, Nautilus PLUS, Triton PLUS Outside Dimensions of black frame only: 10 1/2" long x 6 1/4" wide These are the Accordion style filters Best for use with smaller debris like sand, silt and algae Please make sure your pool cleaner is on the list above. If it is not, this will not fit and you are responsible for return shipping. These do NOT fit the Nautilus or Triton cleaners.