Outer Diameter: 7" Length: 19 5/8" Top Style: 3" Open; Bottom Style: 3" Open; Media: 50 SF Compatible with Easy Clear C550 Hayward CX 550 CX550RE CX550-RE Pleatco PA55 Unicel C-7455 Pure N Clean PC-1245 Filbur FC-1245 Hot Tub Spa Filter. SpiroPure pool and spa filter cartridges offer long-lasting, durable filter media with high dirt holding capacity for clear, sparkling water in your pool or hot tub spa. A strong inner core means increased strength without hindering water flow or filtration performance. Easy to install, durable filter cartridges that allow for high filtration performance and efficiency SpiroPure SP-PS-1245 Hottub Spa Pool Filter Replacement Cartridge. Easy to install, durable filter cartridges that allow for high filtration performance and efficiency.