Anself DIY CO2 Generator System Kit with Pressure Guage Air Flow Adjustment Vavle Water Plant Aquarium Fully installed, direct to use and labor-saving. Well-sealed pipes, leak-proof, non-deformed, never loose. Specialized pressure guage for safe-area indication, pressure watching. Automatic or manual decompression for safer usage and operation. Metal air flow adjustment vavle is preciser than normal plastic product.Cheap, simple to create pure CO2 constantly by chemical reactions.