Tetra Whisper Bio-Bag Large Disposable Filter Cartridge fits Whisper Power Filters 20i, 40i, C 20, 30, 40, and 60. For the ultimate in convenience, choose the 3 pack of assembled Whisper Bio-Bag Cartridges. Replace your Whisper Bio-Bag Filter Cartridge once a month, or when water begins to overflow excessively from the chamber. Available in a 1 pack and 3 pack.
