For Top Fin EF-S Fish Tank Filter Cartridges: Size: 3.7" L x 2" W. ONLY Suitable for BF5 Bettaflo Filters which perfectly match Desktop Aquariums with Element Filters.
Fine Carbon Filtration: The aquarium filter cartridge contain 3 times more activated carbon than other cartridges. Fully absorb and filter impurities or damaging substances to deodorize the water and reduce unhealthy gases.
Further Cleaning: The fish filter's outer layer is made of soft cotton with high-density fiber. The multi-layer cotton traps debris or waste without sucking up your fish, keeping water crystal clear and fresh.
Reliable Replacement Filter Cartridge: The filter carbon is well wrapped in permeable bags inside. No leakage of powders or contamination of water. And the evenly distributed cotton won’t block the normal water flow.
Easy to Use: Before use, rinse the filter cartridges with cool water to remove the outside dust, then put it completely into the filter chamber. Replace it every 2 to 4 weeks to maintain a healthy water environment.
