【High Quality Material】: The Intex S1 model measures approximately 108 x 73 mm (length x width). The pool filter cotton is made of high quality polyester fiber, strong and durable. Our filter sponges are compatible with Intex S1 models and most pool filters on the market to keep your swimming pools, aquariums and spas clean. 【Cost Saving】: Regularly replacing paper filters is part of daily pool maintenance, which increases costs and creates waste. Our reusable and washable filter sponges are an ideal alternative to disposable paper filters. You don't need to change the filter sponge frequently. 【Keep Water Clean and Fresh】: The sponge cover directly covers the water inlet of the filter. It effectively absorbs particles and sediment, thereby improving biological filtration. Its good elasticity, strong tensile force, high speed, and high dust filtration rate allow you to enjoy a safe and healthy massage spa experience. 【Type S1 Filter Element】: Type S1 filter sponge compatible with