ZJchao DIY Aquarium Planted Tank CO2 System Pro Tube 3-spiral Diffuser & Pro Needle Valve Included D501(Green) DIY Co2 generator system D501 Pre-connection,avoid wrong connection; pure and long lasting Co2, promoting plants growing;Transparent circulation piping, fluid flow can be observed at any time.Adjustable pressure relief safety valve acid value (manual + auto). The complete DIY CO2 kit combo for planted aquarium. You can built up your CO2 system within 15 mins. This bottle cap is very well suitable to be DIY CO2 system's accessory that the size fits common PET plastic bottle. Package Included:Package Included: 1 x Pro Needle Valve; 1 x Safety valve (with pressure gauge); 1 x DIY CO2 generator main body (colour by your choice); 1 x Complete connecting CO2 tubing; 1 x English manual;