Dolphin Maytronics 6101611-R4 Climbing Rings, Case of 4 Dolphin Robotic Pool Cleaner Climbing Rings For use with these specific Dolphin Robotic Cleaners: Dolphin Nautilus Plus, Dolphin Nautilus, Dolphin Triton Plus, M200, M400, Discovery, Saturn, Edge, Supreme M3, Supreme M4, Dx3, Dx4, Apollo, Premier Also used with Pentair Prowler 820 and Pentair Prowler 830