Exhale CO2 365In Store Location: K2 No Activation Needed Place The Bags & Wait For The CO2 To Begin! The exhale 365 is a self activated version of the original Co2 bag. The 365 will provide a 4x4 foot or 128 cubic foot space with Co2 for 9 months of which 6 months are peak production. With 3 months of shelf life and 9 months of Co2, that makes a Year. That's the exhale 365! Plants growing under artificial light indoors often lack enough carbon dioxide to