Finest-Filters compatible replacement foam and polycarbon filter cartridges.
These filter pads are compatible with Fluval U2 range of internal filters
The plain filter sponges contain the biological cultures, biologically and mechanically filtering the aquarium water
The polycarbon filter cartridges remove small particles from the water, and the activated carbon chemically filters the water of impurities
Please Note: This is not a Fluval Product. This is a Finest-Filters alternative which serves the same purpose as the original brand.