One package of 3 filter cartridges are included. 

• EFFICIENT FILTRATION: Cleans and removes odors from water in turtle, newt and frog terrariums. 
• DUAL-SIDED MESH: Catches debris and waste to keep water crystal clear. 
• CONVENIENT: Disposable, fully assembled and ready to use. 
• EASY TO REPLACE: Replacing cartridges is fast and easy – change every four weeks. 
• SIZE: Medium size fits TetraFauna ReptoFilter 20 gallon, Viquarium and Decorative ReptoFilter.