JBL ProFlora 500 U disposable CO2 cylinder filled with 500 g CO2 for JBL disposable CO2 system (u system) and for the JBL CO2 sets Easy 1 and Easy 2. Available as singe cylinder and as 3in1 value pack.JBL ProFlora CO2 Cylinder 500 U+ CO2 storage cylinder for all CO2 systems. Supplies aquarium plants with their main nutrient carbon dioxide (CO2) while combatting algae+ easy to install: turn the pressure regulator with internal thread onto the external thread (M10x1) of the storage cylinders+ including mounted rubber stand for good stability+ Dimensions: 31x7.5 cm+ total height with mounted pressure reducer: 37 cm+ TV-tested. Because CO2 liquefies under pressure CO2 pressurised gas cylinders must stand vertically during operation+ disposable cylinder, can not be refilled