The Wonder Climbing Brush Ring - Pack of 4 is a genuine replacement set designed for specific Dolphin Robotic Pool Cleaners, including models like Heavy-Duty, DX3/4, DX6, and Nautilus, as well as Pentair Prowler 820/830. Each pack includes durable rings built to enhance the performance and longevity of your pool cleaner. Easily replace worn-out brush rings to maintain optimal cleaning efficiency. For a comprehensive list of compatible models, refer to the schematics available under "Found in the Following Products." These brush rings ensure a perfect fit and reliable operation, keeping your pool pristine effortlessly.