Dimension One #1561-13

The Unicel 4CH-940 hot tub filter has a closed top and non-standard 1-1/4 inch course SAE threads on the bottom made to fit select Dimension One Spa models. Dimension One Spas have used several different size filters for the same hot tub models depending on year and features. Therefore it’s best to confirm that this filter is the same size as the filter in your Dimension One Spa model before ordering to ensure proper fitment. Filter details: Unicel P/N 4CH-940 Diameter: 4-5/8" Length: 15" Top: Molded Cone Bottom: 1-1/4" SAE Thread 40 sq.ft. Filter Media: 3oz Pleat count: 176 Also compatible replacement for: Dimension One Spas 1561-13 Pleatco PDO-UF40P2 Filbur FC-0177 How long should Unicel hot tub filters last? While most hot tub filters need to be changed every six to twelve months, Unicel brand filters are premium high-quality filters that can last up to two years or more, depending on your level of use and cleaning routine.