ISI Soda Chargers are specially made for making soda in iSi Soda Siphons. Our chargers are made of 100% recyclable steel, non refillable, contains c. 8 g pure CO2. Each charger (gold lacquered) is electronically weighed and measured. Use one charger at the maximum 0.5 liter/1 pint of water. With iSi Chargers you are assured each charge is perfect and pure.