✔️ Designed for Dolphin robotic pool cleaners - S50, S100, Active 10, Active 15, T15, T25, E10, Explorer E20, Nautilus CC, Premium 10, Premium 20, Liberty 200.(Not Compatible With the Nautilus (old), Nautilus CC Pro, Nautilus CC Supreme.) ✔️The ultra fine filter（9991460-R1） is great for particles like algae but struggles to pick up larger debris--BUT Using this filter basket can made it so easy to clean up larger debris from the floor of the pool. ✔️So you can choose which filter basket to use according to your needs，they can all keep your pool in top condition. ✔️If you have any questions, please contact us. Fine Filter Basket 9991459-R1 Replacement Part S50, S100, Active 10,E10,Nautilus CC--- Not Compatible With the Nautilus (old), Nautilus CC Pro, Nautilus CC Supreme.