The photographs in the advertising seem to show that this unit will fit onto a Sodastream gas bottle and even the description for “soda home brewing” seemed to support this. I bought this unit to fit onto a soda stream gas bottle and power a mini keg. The TR21*4 thread will not connect to a Sodastream bottle. I now know that this apparently requires a CGA320. I believe that this unit came from China so the return postage is expensive and I’m stuck with a unit I cannot use.