Intex filter cartridge S1 for Spa This filter cartridge is specially designed for all Intex Spas. For clean water in your spa, it is important to replace the filter cartridge every two weeks, depending on use. To ensure that the filter cartridge is still good, you can check it every week and rinse off light dirt with a garden hose with a powerful jet of water. Specifications: Color: white, blue Material: plastic Diameter: 10.8 cm Height: 20.1 cm Type: S1 Contents: 2 Filter cartridges (S1)