Keep your aquarium crystal clear with the biOrb Service Kit Filter Cartridge. This kit includes a cleaner pad and water conditioner that is perfect for all water types. Designed for external use, this filter cartridge is compatible with 1 gallon tanks and above. The biOrb Service Kit Filter Cartridge is a must-have for any aquarium owner. The kit includes everything you need to keep your tank clean and clear, and the water conditioner will help to maintain a healthy environment for your fish. This unit is easy to use and is perfect for those who want to ensure their aquarium stays in top condition.