The Gro1 CO2 Regulator is the perfect tool to help you control and maintain your optimum CO2 levels for your plants. It has an easy-to-adjust flow meter (adjustable to 0.5 – 15 cubit feet per hour), a pre-set regulator, and a solenoid valve. Easily attach the included tubing to a fan for even CO2 distribution throughout your grow room. With this CO2 regulator, you can speed up plant growth and shorten up the time for harvesting!!!