well they are different
they wouldnt be much of a company if they only sold 1 thing
if u want to fill an air tank you need something similar to what you have in the 4th link for air. id suggest you go on a safety course tho cos it can be dangerous if you dont know what your doing (ypc do one for free)
the differences are the pressure the tanks go up to and air have a regulator on the end (usually given away by the big guage on it) rather than just a valve like co2
they wouldnt be much of a company if they only sold 1 thing
if u want to fill an air tank you need something similar to what you have in the 4th link for air. id suggest you go on a safety course tho cos it can be dangerous if you dont know what your doing (ypc do one for free)
the differences are the pressure the tanks go up to and air have a regulator on the end (usually given away by the big guage on it) rather than just a valve like co2