Stock up on Sodastream carbonators to keep the sparkling water coming. This set includes two carbonating gas cylinders, each one bubbling up to 60 liters of water in your Sodastream sparkling water machine.We now offer an in-store carbonator cylinder exchange program. Bring your empty CO2 cylinder to Crate & Barrel and exchange it for a replacement at a 50% discount. Empty cylinders are returned to the manufacturer for reuse.