Intex PureSpa Type S1 Pool Filter Cartridges 4 Pack Replacement 29001E Blue Intex PureSpa Type S1 Filter Cartridges come in a convenient 4-pack, consisting of two factory-sealed twin packs. These high-quality replacement filters are designed specifically for all Intex PureSpa models, ensuring your spa water remains clean and clear. The heavy-duty Dacron paper construction features more pleats for better filtration and efficiency. Easy to clean and maintain, these S1 cartridges help prolong the life of your spa's pump and heater by capturing dirt and debris effectively. Measurements: • Height: 2.8" • Outer Diameter: 4.25" • Inner Diameter: 1.6" #Casual