As of January, 2016 Sodastream's official website offers two different sizes of carbonators, or CO2 replacements, each with a different price. The 14.5-ounce carbonator costs $29.99 for a single carbonator, or $59.99 for a pair.
Additionally, a single 33-ounce carbonator costs $49.99 while a pair costs $99.99. These carbonators are considered spares by the company, and cannot be exchanged online, although local retailers may be able to exchange the empty cartridges for full ones. This is because the U.S. Department of Transportation considers the CO2 cartridges to be hazardous material and place strict rules on how they can be shipped.