The Aquatic Reptile Internal Filter is designed for terrariums that hold turtles and other aquatic animals. It works hard to keep terrariums clean. Each filter comes with a replaceable carbon cartridge that removes odor, waste, and debris from water. Also included are suction cups and hanging clips that make installation quick and easy. A protective grate is in place to prevent the animal from entering the filter. Replacement cartridges for this filter are sold separately.