Having extra carbonating bottles for your SodaStream machine is a great way to keep a variety of drinks for your guests. A special hermetic sealed cap ensures that you keep the carbonation in so your soda stays fresh and fizzy. Each bottle lasts up to 2 years and replaces 2500 bottles and cans from store-bought drinks that would otherwise be thrown in a landfill. BPA-free. Includes two bottles plus bonus bottle.