OK, so I know that they go to 3K, but I guess the question is, how many times would I be able to refill my Hatsan Flash QE with it? I have a buddy that dives and will lend me a full tank to play with, but the plumbing alone is near a hundred bucks. Not keen on spending that for a test. I know a 4500 PSI bottle is the way to go, but this is getting pricey.