Cow methane bag designed to capture methane gas produced by livestock as part of their normal digestive process. Methane resulting from this process account for 26% of the total U.S. methane emissions.
https://s3-us-west-1.amazonaws.com/h...e_backpack.jpg
More:
https://www.epa.gov/ghgemissions/ove...-gases#methane
Previously:
https://www.homemadetools.net/forum/...7366#post85606
https://www.homemadetools.net/forum/...379#post116688