Eheim Classic Filter Pad 2217 includes Coarse, Fine, and Carbon filter pads in packs of three.
Coarse: EHEIM's Coarse Blue Filter Pad is used as a parting layer between the mechanical (EHFIMECH) and biological filter medium (EHFISUBSTRAT/EHFISUBSTRAT PRO). Coarser particles are restrained and are thus removed from the water prior to entry into the biologically acting filter layers. This filter material may be rinsed and re-used; rinse in tank water or dechlorinated tap water to keep it's biological filtering capabilities.
Fine: Eheim's Fine White Filter Pad is used as the last stage of filtration, to polish water of very fine particles before it is returned to the aquarium. This Filter Pad cannot be rinsed and re-used; once it has become soiled, it should be replaced to avoid damage to the motor head of the filter.
Carbon: Replacement carbon filter pads for EHEIM Classic external filter models 2215 and 2217. Carbon filter pads are instrumental in the chemical filtration stage. For use only with EHEIM filter media container. Three, black carbon filter pads per package.