Whisper 10i Internal Filter and 3-Pack of Bio Bag Filter Cartridge Refills Whisper 10i Internal Filter and 3-Pack of Bio Bag Filter Cartridge Refills Designed for Use in Smaller Aquariums Up to 10-GallonUses Medium Whisper Bio-Bag Cartridges Uses Medium Whisper Bio-Bag Cartridges Provides convenient 3 stage filtration Conveniently Assembled and Ready-to-Use