Dolphin Nautilus Plus/Triton Plus Spring Cartridge Filter Panels (4pack) Spring Cartridge 4-Filter Panel Set for Nautilus Plus - Triton Plus 4-Pack Set - Used for Spring Cleanup- larger particle cleaning- Also used for Supreme M4 Supreme M5 Wave 65 Wave 90 Liberty Not for older plain Nautilus and plain Triton units (for Nautilus Plus and Triton Plus) Verify that this is the appropriate set for your Pool Cleaner, BEFORE ordering!