Perfect Fit: This Robotic pool cleaner filter replacement compatible with Dolphin Nautilus CC Plus (Note: Do not fit Nautilus CC or Nautilus CC Pro)?and M200, M400, M500, replaces part# 9991432-R4; Dimensions: 10 1/2'' x 6 3/8'' Ultra-Fine Filtration Technology: Ultra-fine pleated filter panel efficiently captures more and finer debris, including hair, leaves, dust, sand, and particles for a crystal-clear pool Long-Lasting Performance: Strong ABS support frame stands up to cracking and corrosion, maintaining structural stability for consistent filtration and smooth water flow Easy to Clean: Premium polyester material and well-spaced pleats allow debris to rinse off easily, saving time and effort on maintenance; clean every 4-6 weeks for optimized performance Brand Service: If you have any questions, please ask us in time and we will answer them for you.