Compatible with gas cylinders approved for sparkling water makers from all major global brands. The Aarke sparkling water maker is made of stainless steel. It is designed to be extremely compact both inside and out. Nevertheless, it features a unique safety system consisting of three independent safety valves. The lever carbonates the water and automatically releases the pressure in the bottle. Simply press the lever and hold it until you hear a buzz, then release it and unscrew the bottle from the machine. It couldn't be easier. Aarke is the world's first sparkling water maker equipped with a complete stainless steel casing. Forget about old plastic soda makers and opt for a device whose timeless design perfectly complements your kitchen countertop and will delight you for many years. The Aarke sparkling water maker is designed to be compatible with the widely used SodaStream CO2 gas cartridge (60L). This keeps you flexible, as SodaStream already has an established network of 70,000 stores worldwide. Warning: Please use the sparkling water maker exclusively with original Aarke PET bottles. The PET bottle is not dishwasher safe.