The carbonator is a metal canister that holds Co2 under pressure and fits into your Sodastream maker. There are two sizes. The standard makes 60 liters of soda, and there is a larger one that makes 130 liters. The larger one is wider and may not fit in all machines.
How well it Works
I have never had a canister of Co2 malfunctions. I just screw it in to my machine and I can not even see it. It is compact and I like that I do not have to look at the canister since it is hidden inside the black plastic part of my soda maker
How to get a Refill of Co2
Generally you can order these online and over pay for them, or simply take your old used up one to one of the stores listed below and exchange it for a new one. Simple unscrew the old one and take it in for a replacement and you are back in business.
Replacement or Spare
Your other choice is to buy a replacement without returning your old one. This way you never have to worry about running out of fizz for your soda. Personally I just bring mine in and get a replacement. I do not use it that much so the danger of running out is not as urgent as it might be for some.
How much do they Cost
To purchase a replacement that will make 60 liters of soda, the cost is generally $29.95. The cost to just get a refill and turn in your used canister is only $14.95. If you want to return your 130 liter size and get a replacement you will have to go to Staples only or some specialty stores might carry them. The cost to get a 130 liter size replacement is $29.95 If you are switching from a 60 L to a 130 L first make sure it will fit in your machine and then check with Staples to see if you might be able to turn in your smaller one for the larger size.
Where to buy
If you want more info on the Sodastream maker please read my review of the Sodastream Genesis
Final Thoughts and Rating
This is a can of Co2 so I am not sure exactly how to rate it but since it works fine and is easy to refill I will give it 5 stars. I love my Sodastream more and more every day as I add a little fizz to many drinks like crystal light, juice or even flavored teas.