and , reusable foam box.Suitable for Intex Bubble and Jetted Pure spas.for the replacement of the S1 box. Replacing the filter elements of the paper filter is part of the daily maintenance of the pool.These clean, reusable foam filters will cut your costs.The initial cost of the cartridge is slightly higher than the cartridge, but the life of the cartridge is longer for a long time.More durable than cardboard, it can be washed and reused many times.Size: 10.8 x 7.3cmDrilling of the central hole: About 4 cmMaterial:SpongeColor:BluePackage content: 18 x filterSpongesOnly the above package contents, other products are not included.Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing.The allowable measurement error is 1-3cm. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.