These are genuine replacement Poly/Carbon Cartridges for the Fluval U Aquarium FilterS. The Fluval Poly/Carbon Cartridges have two unique filtering sides that combine to provide thorough and effective chemical filtration, the crucial second stage in the filtration process. The polyester filter pad side filters out fine debris and contaminants. The carbon side filters out harmful liquid substances, colourants and odours. Geniune Fluval Part Polyester/Carbon cartridge provides thorough and effective chemical filtration Polyester filter pad side filters out fine debris and contaminants Carbon side filters out harmful liquid substances, colourants and odours Available in 3 sizes to fit; U2, U3 and U4 Filters
