JBL ProFlora Taifun Glass Midi is a small, attractively designed CO2 diffusor with ceramic membrane for even enrichment of the aquarium water with the basic plant nutrient, carbon dioxide (CO2). With special ceramic for particularly small and even-sized CO2 bubbles. High quality glass design, easy to clean. Fits all CO2 4/6 mm hoses. Fits all current CO2-Systems. For aquaria from 20 up to 400 litres water volume.available in 3 sizes:JBL ProFlora CO2 Diffusor Taifun Glass Mini: for aquariums: 40-120 LiterJBL ProFlora CO2 Diffusor Taifun Glass Midi: for aquariums: 40-300 LiterJBL ProFlora CO2 Diffusor Taifun Glass Maxi: for aquariums: 160-300 Liter