High-quality filter cartridge designed to absorb harmful components in water and create a healthy environment for fish. Utilizes treated zeolite for effective filtration and absorption of water impurities, ensuring durability and long-lasting performance. Includes 6 large replaceable filter cartridges for convenient and quick installation, making it easy to use. Compatible with Whisper Bio-Bag external filter PF20, 30, 40, 60, Whisper external IQ20, 30, 45, 60, Whisper 20i and 40i internal filters, and TetraFauna ReptoFilter 50 gallon (125 GPH). Recommended replacement every 2-4 weeks to maintain optimal water quality for your aquarium. Description: Introducing our premium filter cartridge for aquariums, designed to provide a healthy and thriving environment for your fish. Made with treated zeolite, this cartridge effectively filters and absorbs water impurities, ensuring a clean and clear habitat for your aquatic pets. The durable construction and 6 large replaceable filter cartridges make maintenance a breeze, while the quick installation process makes it easy to use. Compatible with Whisper Bio-Bag external filter PF20, 30, 40, 60/Whisper external IQ20, 30, 45, 60/Whisper 20i and 40i internal filters and TetraFauna ReptoFilter 50 gallon (125 GPH), this cartridge is versatile and reliable. For optimal performance, we recommend replacing the filter every 2-4 weeks to maintain water quality. Item Name: Filter Cartridge Material: Zeolite Features: Easy Installation, Convenient, Durable, Effective Size Details: L: 18cm/7.09", W: 13cm/5.12" (Approx.) Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 6 x Filter Cartridge