and high quality,Reusable foam box.Suitable for Bubble and Jetted Pure-spasfor Replacement of S1 carton.Replacing the filter elements of paper filter is part of the daily maintenance of the pool. These cleaning and reusable foam filters will reduce your cost.Initial cost of this cartridge is slightly more than a paper cartridge yet will outlast a cartridge by a .More durable than the carton, and it can be washed and reused many times.Center hole drilling: Approx4 cmcolour: blueMaterial: SpongeSize: 108x73cmPackage Contents:9 x Filter SpongesOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.