Key Features Keeps water crystal clear and healthy Reduces Algae 1x Filter Cartridge and 1x Algaway pad included. 1 Month supply Fits the CF1 Internal Filter One Month Service Pack for the Interpet Internal Aquarium Filter CF1 It is recommended that you change the filter and Algaway pad in the CF1 filter, every month. Changing the filter pads ensures your aquariums stays clear, clean and algae free. Carry out a 25% water change, using a Tapsafe treatment to treat the water. Remove and discard the old filters and slip the new filters easily into place. One Month supply. Specifications 1x Filter Cartridge 1x Algaway Cartridge Fits CF1 Interpet Internal Aquarium Filter