Its pretty easy to figure out what size a compressed air tank is. If your a noob to paintball it could be a little confusing. Let me break it down for you.

The first number is the cubic in of the tank, that’s how large the tank actually is. Usually sizes are 45, 47, 68, 70, 72 and 90. The second number tells you how much air the tank can hold inside read in PSI (ponder per sq. inch), this will read 3000 or 4500. There are 5000psi tanks out there but its more of a gimmick than anything else because most fields will not be able to fill to 5,000 PSI.

So for an example. a 68/3000 holds less air than a 68/4500 becuase the 4500 can hold more air in the same amount of space than a 3000.