Our Blueflo Pool & Spa Filter Cartridge Replacement compatible with Watkins 31489, Filbur FC-3915, Unicel C-6330, C-6430, C-6430RA, Pleatco PWK30, PWK30-M, PWK30-4, SD-00328, 71825, 73178, 73250, P/N0969601, PDC510-AFS, SD-00704, CCP389 filtration cartridges.