One soda charger will prepare up to 1 litre of soda water. Every charger is weighed individually, in order to ensure it contains the correct amount of gas. Ingredients: 7.5 g CO2 (E290). The soda chargers are made of recyclable steel (colour gold) and are non-refillable. Only ever use the Kayser SODAsiphon with Kayser soda chargers.