This cap is threaded for use with all mini keg sizes.
This is the replacement part for the cap that comes with the Basic Tap Kit.
Pro Tip:
This cap can be converted for use with any 1/8" NPT threaded adaptor, like the 90° 1/4" barb pictured below. This will allow customization options like this cooler setup. This will requirepermanently removing M8 thread and using a 1/8" NPT machinist tap.