The Pondmaster 190 Filter Replacement Media pack includes 2 pads: one foam filter pad and one coarse polyester media pad. Using these two media together in your pond filter provides chemical and biological filtration. These pads are washable and reusable.Chemical and biological filtration padsWashable and reusableEach set contains 1 foam filter pad and 1 coarse polyester media padServes as replacement for the PMK 190 Kit. The foam filter should be rinsed regularly to maintain maximum flow. The coarse polyester acts as a substrate for biological filtering and should be carefully rinsed in a bucket of pond water to maintain the beneficial bacteria growing on it.Pad Dimensions: 10"L x 8"W x 1.5"D