The Climbing Ring Replacement for (Compatible with) Maytronics Dolphin 6101611-R4, Fits M200/M400/M500, Nautilus/CC Plus, and DX3/DX4/DX6 and Mor Perfectly Fit: Our climbing ring replacement kit is compatible with Dolphin Robotic Pool Cleaners like M200, M400, M500, Nautilus, Nautilus CC Plus, DX3, DX4, DX6, Aquarius XL, Premier, Oasis Z5i. Great Value: The package comes with all four climbing rings 6101611-R4, also fit Sigma, Triton (old), Deluxe 4/5, Apollo Plus, Wave 65, Endeavor, Edge, HD, Saturn (old), Atlantis, Apollo, 3001, 2X2, Wave 2X2, Prowler 820/83 Premium Quality: Our replacements are made from PVA; ensure to last longer. They are perfect for maintaining your pool safe and functioning properly. Simple installation: Soak climbing ring thoroughly in water until they expanded and softened enough to install on rollers. Slide them in slowly and ensure that they are sitting in their designated space.