Help keep your aquarium crystal clear with Tetra’s Whisper Bio-Bags. These disposable filter cartridges are easy to use and work to keep your fish tank in tip-top condition. The ultra-activated carbon is designed to absorb discoloration and foul odors while the dense, double-sided mesh works to trap debris and fish waste. These Bio-Bags are designed to fit Whisper Power Filters 10, 10i, E, J and MicroFilter (not included). Best of all, they come pre-assembled and ready to use!