These fine filter pads are for use with the eheim professional 2 range of filtersr 3 phenol free filtration pads in total that will add a layer of fine filtration to your filter capable of sieving fine particles and pollutants to improve the freshness and cleanliness of your aquarium water r for best results use above biological filter media to ensure that the water is thoroughly polished easy to install replace once they become cloggedr compatible withr 2026 2126 2028 2128 2226 2326