DR. moss 3Spiro glass Co2 Diffuser 25mm -for Aquarium live plants - Moss Fern Plant Java Valve ATOMIZER Suction cup - Regulator Solenoid The high efficiency of diffusing carbon dioxide. CO2 bubble counter is built in this device. Easy to install and use,with no extra power required. Suitable for tanks 15 - 50 gal (60L - 200L) Suction cup (free) x2