Dolphin Maytronics 99954305-RK1 Filter Bag Assembly & Bottom Lid Conversion Kit 3 Complete Filter Bag Conversion Kit - Includes Bottom Lid and Filter Bag Dolphin Nautilus and Dolphin Triton Conversion Kit to Bag Filters Filter bag systems generally last longer than the cartridge systems between cleanings. Allows you to replace the cartridge filters that come standard on Dolphin Nautilus, Triton some other dolphin pool cleaners