AQUANEAT Aquarium Bio Sponge Foam Filter Media Pad Cut-to-fit for Fish Tank Sump Pond 17" x 11" x 1/2" to 1"Brand: AQUANEAT Features: Each set has 3 foams ( 1 x Coarse, 1 x Medium, 1 x Fine), the combination of triple density sponges can traps both large and fine particles working together to produce crystal clear water in your aquarium. Good for both mechanical and bio filtration Special egg crate design offers more surface area for filtration. Can be cut to fit and used as a pre filter for any aquarium or pond filter, sump, wet dry, canister, power filter