Published December 05, 2019 08:49 What kind of metal are your cylinders made from? The body of our cylinders are aluminum, while the valves are brass. Related articles I live at a high altitude will this affect my cylinder? Are CO2 cylinders safe for the environment? What's the environmental impact of releasing CO2? Does a customer get a deposit back for turning in their empty cylinder? I no longer want my SodaStream cylinder. What should I do with it? Help! There are no stores in my area to that sell gas refills!