Keep your aquarium clean and healthy with these Top Fin PF30 Silenstream Filter Cartridges. Designed for tanks up to 50 gallons and fresh water, these internal filter cartridges are specifically made for Top Fin filters. These cartridges boast a high-quality construction and effectively remove impurities, keeping your fish happy and healthy. Perfect for fish enthusiasts, these filter cartridges are a must-have for maintaining a clean aquatic environment.