The kit now includes a check valve to protect your regulator (not shown in all the photos yet)
Sodastream threads are the same worldwide with the exception of Australia and New Zealand.
If you want to convert a Pro Tap Kit, Pop Tap Kit, or a Growl Tap Kit so that you can use it with a sodastream canister then here is everything you need. Buy them as a kit and save a few bucks. Now you can use it with a Basic Tap Kit if you have the new cap with the larger thread, see image below.