Reusable Washable Filter: Changing your paper filter cartridge is part of your routine maintenance for your pool and regular replacement of the cartridge can prove costly. These washable and re-usable foam filters will reduce your costs. Long Working Time: Initial cost of this cartridge is slightly more than a paper cartridge yet will outlast a cartridge by a . Durable: This Foam filter will outlast your paper cartridges and can be washed and re-used several times over. Reusable Washable: Advises changing a paper cartridge each week, whereas these foams can simply be washed and put back. Keep Water Clean:Will be a great water cleaner for swimming pool. Specifications: Fitment:For S1 Type Material: Sponge Color: blue Size():10.8x7.3cm(Approx) Center Hole Drilled:40mm(Approx) It takes 2 hours for the compressed product to recover Package Contents: 12 x Filter Sponge 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.