S.T. International CO2 Supply System Starter Kit for Aquarium Plants Easy and convenient kit for plant aquariums CO2 (carbon dioxide) is the most important nutrient source to water plants Watch your plants grow and thrive with a steady supply of CO2 7-piece kit includes Disposable CO2 Cartridge (95g), Cartridge Stand, CO2 Regulator, CO2 Bubble Counter, CO2 Atomizer, Check Valve and Suction Cup