Strong Compatibility: The specific size of our aquarium filter cartridge is 2.1 in L x 3.7 in W. It is very suitable for Top Fin BF5 BETTAFLO FILTER & DESKTOP AQUQRIUMS. With this aquarium filter cartridge, you can keep your water healthy every moment. It contains 6 pack aquarium filter cottons, which you can change every 2-4 weeks.
Excellent Filtration Performance: The filter cotton is made of cotton and carbon and has 3-layer filtering effect, which can filter and absorb 99% of the sundries to fish, so as to keep the water source clean and the healthy growth of fish.
Long-term Replacement of the Aquarium Filter: According to the test, the filter cotton has already withstood too much sundries for no more than four weeks, so you need to replace it with a new one to keep the water source healthy and clean at all times. Suggest to change filter cartridge every 2-4 weeks.

WITH ROTATING BIO-WHEEL: Patented Bio-Wheel technology provides excellent wet/dry biological filtration
MULTI-STAGE FILTRATION: Delivers mechanical, chemical and biological aquarium filtration to maintain a clean aquatic environment
MARINELAND FILTRATION PRODUCTS: Count on Marineland brand for the most reliable, technically advanced aquariums and accessories on the market