Changing your paper filter is part of your routine maintenance for your pool and regular replacement of the can prove costly. These washable and re-usable foam filters will reduce your costs. Initial cost of this is slightly more than a paper yet will outlast a by a This Foam filter will outlast your paper cartridges and can be washed and re-used several times over. Advises changing a paper each week, whereas these foams can simply be washed and put back. You should see a foam filter last around 2 months. Specifications: colour: blue Material: sponges size: 20cm*10cm*10cm/7.9*3.9*3.9 inch(H*D) Center Hole Drilled:.40mm Package Contents: 3*Reusable 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.