The Whisper Ex20 aquarium power filter offers a host of modern conveniences and advanced filtration capabilities to keep your aquarium clean, clear and healthy. Benefits and features include: Hands-clean squeeze-to-open filter cartridge design keeps your hands-free of messy carbon pads Keep your fish healthier by never forgetting to change your filter cartridge with TimeStrip color tabs included with each filter cartridge Extra-quiet, in-tank motor design promotes even quieter Whisper operation, eliminates priming and lowers the filters profile Promote circulation and lessen build-up with rounded filter chamber design Enhanced biological grid promotes optimum bacteria growth.Whisper Ex20 Power Filter Specifications. For Aquariums up to 20 gallons 110 gph Requires 1 medium size Whisper Filter Cartridge