Premium Material Approx 108 x 73mm (L x W) for Intex Type S1. The pool filter cotton is Made of high quality sponge. Our pool filter sponge is suitable for Intex Type S1 and most pool filters on the market, keep the pool, aquarium and spa clean. Save Cost Regularly replacing the paper filter cartridge is part of daily pool maintenance, which leads to increased costs and waste. Our reusable and washable filter sponges are an ideal substitute for disposable filter paper. You don't need to change filter sponges frequently. Keep Water Clean and Fresh The sponge cover directly on the water inlet of your filter. Captures particles and deposits and improves biological filtration. Good elasticity, strong tensile force, fast dust filtration speed, high filtration rate, with this filter, you can enjoy a safe and healthy massage spa. Tips These washable and reusable sponge filters can reduce your costs. We recommend changing it once to two weeks to achieve better filtration effect to keep the