Let it breathe! ExHale Homegrown CO2 Bags provide a continuous supply of carbon dioxide with no need to refill bottles or use expensive regulators, generators and monitors. The power of the product lies in the mycelial mass, which is growing on organic matter inside the cultivator, and the one-way breather patch located on the bag. Supplies up to 1500 ppm CO2, depending upon room size and ventilation for up to 6 months. Easy to use, just hang slightly above the height of the plants in your grow space. Each bag will provide 4-6 plants with a continuous shower of CO2. No need to turn it on or off -- simply leave it alone to do its job.