Features: 1. All-aluminum alloy body design, hard oxidized, safe and durable, far better than plastic hose, easy to install 2. Aluminum alloy cap, good pressures resistance, prevent the cap from rupturing 3. Special fish tank low pressures meter, accuracy: 0.02 MPa 4. Adjustable valve with upper opening, easy to clean even if the regulator is clogged inside 5. Accurately adjust carbon dioxide emissions, use copper needle valve fine-tuning regulator to ensure accuracy 6.12V miniature waterproof solenoid valve (not included), compared with 110V solenoid valve, completely avoids the danger of 110V electric shock, including soaking water, reducing temperature and reducing noise. Only need to adjust the carbon dioxide output once, and with the timer The lights are used synchronously. 7. All-aluminum precision check valve bubble counter completely avoids the danger of plastic threaded parts breaking due to softening. 8. This aquarium CO2 DIY system is designed for low cost plant tanks, saving money and getting more fun. includes:Choice 1: 1 x Aquarium CO2 Generator Kit 1 x 1.5m Trachea Choice 2: 1 x Aquarium CO2 Generator Kit 1 x 1.5m Trachea 1 X Bubble Counter Choice 3: 1 x Aquarium CO2 Generator Kit 1 x 1.5m Trachea 1 X Bubble Counter 1 X Solenoid Valve Choice 4: 1 x Aquarium CO2 Generator Kit 1 x 1.5m Trachea 1 X Bubble Counter 1 X Thinning Device Choice 5: 1 x Aquarium CO2 Generator Kit 1 x 1.5m Trachea 1 X Bubble Counter 1 X Solenoid Valve 1 X Thinning Device