and high quality,Reusable foam box. Suitable for Bubble and Jetted Pure-spas.for Replacement of S1 carton. Replacing the filter 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 is slightly more than a paper yet will outlast a by a . More durable than the carton, and it can be washed and reused many . Center hole drilling: .4 cm colour: blue Material: Sponge Size: 10.8x7.3cm Package Contents: 9 x Filter Sponges Only 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.