① Pool filter sponge, filter sponge for Intex type S1, for Whirlpool filter, reusable and washable sponge filter, filter sponge type S1 (8 pieces) ②High quality material: ok. 108 x 73 mm (L) x W ) for Intex type S1. The cotton pool filter is made of high-quality polyester fiber, which is strong and durable. Our pool filter sponge is suitable for Intex type A and most pool filters on the market, keeps your pool, aquarium and spa clean. ③Cost savings: Regular replacement of the paper filter cartridge is part of the daily maintenance of the pool, leading to increased costs and waste. Our reusable and washable filter sponges are the perfect replacement for disposable filter paper! No need to replace filter sponges frequently. ④Keep water clean and fresh: cover with sponge directly at the filter water inlet. Captures particles and sediments and improves biological filtration. Good flexibility, strong adhesion, fast dust filter speed, high dust filtering rate, with this filter you can enjoy a safe and healthy spa in the massage pool. ⑤Tips: These washable and reusable sponge filters can reduce costs. We recommend replacing it once every two weeks for a better filtering effect to keep your pool clean.