Some Commonly asked questions are
What are the thread size of a Paintball Air Tank Neck (Part that fits into the bottle)?
it's 5/8-18 UNF
Whats the Size that fits into the Gun or ASA (Air Source Adapter)?
Its known as CGA 320 which has the following specs of 13/16" (.825") outer diameter and 14 threads per inch. for more details there is a helpful chart at CONCOA Precision Gas Controls
How can I fill a Paintball Tank ?
We'll start with what you can't fill it with, a car compressor isn't going cut it, you'll need something capable of filling up to 200 bar, this type of compressor can be found at a local dive shop or you can pop into our Paintball Shop. You can also invest in a High Pressure Stirrup pump, but be prepared for this to take some time! Another way to fill, and probably the easiest is to decant from a scuba tank into a smaller Paintball or Airsoft High pressure air tank, to do this you'll need a scuba refill station
For more info please see our specialist Paintball HPA Air Tank Regulator collection