The Fluval A456 fits the following filters:
The Fluval Nano Replacement Aquarium Bio-Foam 2-Pack includes two pieces of Fluval Nano Bio Foam that help trap debris and house beneficial nitrifying bacteria in your aquarium tank. This aquarium Bio-Foam fits the Fluval Nano Filter and provides efficient mechanical filtration. This aquarium foam filter prevents debris bypass and promotes efficient water flow.
Fluval Nano Replacement Aquarium Bio-Foam 2-Pack specifications: