Custom Automated Products Carbon Dioxide Regulator The CAP carbon dioxide Regulator will allow you to maintain ideal CO2 levels for optimal growth. Featuring an accurate, easy-to-adjust CO2 flow meter, a preset regulator that never needs adjusting, and a solenoid valve. Includes the tubing needed to disperse the CO2 evenly by attaching it to an oscillating fan. The flow rate is adjustable from .5 - 15 cubic feet per hour. Requires a compressed CO2 tank, and a digital CO2 controller OR automatic timer.