Keep your tank water clear and your filters running smoothly with Tetrafauna ReptoFilter Cartridge Replacements. This three-pack includes cartridges that are fully assembled and ready for use. The outer layer features a dense, dual-sided mesh that helps trap debris. For the chemical stage of filtration, each cartridge contains Ultra-activated carbon that helps remove odors and discoloration as water passes through. Tetrafauna disposable filter cartridges are super convenient and easy to install so your aquatic habitat can stay clean and healthy. Key Benefits Includes cartridges that are fully assembled and ready for use The outer layer features a dense, dual-sided mesh that helps trap debris For the chemical stage of filtration, each cartridge contains Ultra-activated carbon that helps remove odors and discoloration as water passes through Super convenient and easy to install so your aquatic habitat can stay clean and healthy Disposable filter cartridge for easy clean up