and high quality Reusable foam filter box Compatible with Intex Bubble and Jetted Pure-spas Replacement for S1 cartridge Replacing paper filter elements is part of regular pool maintenance These reusable foam filters help reduce ongoing costs Higher initial cost compared to standard cartridges but offers longer service life More durable than paper cartridges and can be washed and reused multiple times Size: 10.8 x 7.3 cm Center hole diameter: Approx 4 cm Material: Sponge Color: Blue Package Contents: 18 x Filter Sponges The package includes only the items listed above; other products are not included Note: Lighting and display settings may cause slight color variations between the image and the actual item Measurement allowance: +/- 1-3 cm