Ideal Replacement Cartridges with Strong Compatibility - It is perfect compatible with Top Fin Silenstream Power Filters PF10. The specific size of our aquarium filter cartridges is 5.5 in L x 3.1 in W. With this aquarium filter cartridge, you can keep your water healthy and clean every moment. | Excellent Filtration Performance - The filter cartridges is made of high density cotton + 50% more nutshell activated carbon + zeolite, which has 4-layer filtering effect to filter and absorb 99% of the impurities, especially absorb ammonia and nitrogen in the water. So as to keep the water source clean and the healthy growth of fish. | Long-term Replacement of the Aquarium Filter - For the health of your fish and other creature, suggest to change filter cartridge every 2-4 weeks to keep the water source healthy and clean at all times. The filter cotton has fully absorbed and filtered the impurities in the aquarium. | Easy to Install: Please remove used cartridge and rinse new cartridges with water to remove the outside dust, then fully seat it into the filter chamber. Replace it every 2 to 4 weeks to maintain a healthy water environment. Protect the health and safety of your fish all the time. | High-quality After-sales Service: Zuqqony produces high-quality filter cartridges for fish tank, and is in a leading position in the quality and craftsmanship of all our products. We maintain a thorough quality control process to ensure compatibility with QuietFlow models. If you have any questions, please feel free to contact us!