Tetra ReptoFilter 125GPH Reptile Terrarium Filter and 3-Pack of ReptoFilter Filter Cartridge Refills Tetra ReptoFilter 125GPH Reptile Terrarium Filter and Bonus 3-Pack of ReptoFilter Filter Cartridge Refills Terrarium Filter for Frogs, Newts, and Turtles Three stage filtration It's a biological filter - Bio-Foam cultivates aerobic bacteria, which eliminate toxic ammonia and nitrites 125 Gallons Per Hour, Perfect for Terrariums 55 Gallons or less