Microfiltration technology The Spring Filter Cartridges trap larger debris while allowing finer debris to pass through, helping prevent clogging when the pool is especially dirty. Compatible with multiple Dolphin Robotic Pool Cleaners Perfectly compatible with S50, Active 10, Echo, T15, Proteus DX3, Saturn (new), Cayman, Escape, Nautilus CC, Encore, E10, Solo, and Advantage. Maytronics Part Number: 9991460-R1. Durable construction ABS plastic frame provides sturdy support for the filter layer and helps prevent breakage during operation. Common models include the Dolphin e10 Ultra fine Filter. Ultra Fine Filtration Basket Includes one Ultra Fine Filtration Basket, same as the original model number 9991460-R1. Use scenarios - After storms or periods of heavy debris, to reduce clogging and maintain cleaner water. - As a replacement or spare filter for regular maintenance of Dolphin robotic pool cleaners listed above. - When using models that require the 9991460-R1 basket to ensure optimal filtration performance.