Widely Compatible: This large aquarium filter cartridge is compatible with Whisper Bio-Bag external filter PF20, 30, 40, 60; Whisper external IQ20, 30, 45, 60; Whisper 20i & 40i Internal filter and ReptoFilter 50 gallons (125 GPH). Unit Size: 5.1 * 6.7 inches

3 Layer Filtration for Clearer Water: Features a double-sided filter mesh structure that efficiently captures fish waste, food particles, and suspended debris. The built-in activated carbon layer adsorbs odors, impurities, and discoloration-causing chemicals, helping maintain pH balance and ensuring long-lasting water clarity

Simple Operation, Ready-to-Use: Each filter cartridge is pre-assembled at the factory. Users simply rinse for 30 seconds before use. Replacement is effortless and requires no additional tools. For optimal filtration performance, we recommend replacing every 2-4 weeks (frequency may vary depending on tank density)

Cost-Effective 16-Pack: 16 pack filter cartridge set, designed for long-term use and multi-tank setups. Economical and convenient, it eliminates frequent replenishment while helping maintain a healthy aquarium ecosystem. Please feel free to contact us regarding any usage inquiries for a prompt and satisfactory resolution

Durable Design, Durable Stability: The built-in ABS frame ensures uniform distribution of activated carbon and filter media, guaranteeing thorough filtration of every drop of water, then also prevents impurities from clogging, thereby protecting the filter's performance, extending equipment lifespan, and reducing maintenance costs