Published April 12, 2019 17:53 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? Does my CO2 cartridge have a lifespan, or expiration date I need to use it by? Does a customer get a deposit back for turning in their empty carbonator? How do you get a CO2 refill when there are no exchange stores in the area? I no longer want my SodaStream cylinder. What should I do with it?