it's basically a pin valve with a regulator below it. not much else. i believe there are on/off tanks, never used one so i'm not 100% sure, but just buy an on/off asa. that way, you can get any tank.
no it won't work on an HPA tank. first of all, it doesn't have a regulator. second of all, i don't think someone at your level should be switching valves yet, if ever. I don't do it, even though I know the procedure, just to dangerouse. Just buy a crossfire tank, they are the best for the money.
just get a drop of uni mount with an on/off on it. the SP on/off valve that goes into the tank will NOT work with HPA. you have to have a reg with HPA.
only adjustable tanks have on/offs as far as i know. (you can turn the pressure down to 0 or theres a switch where you can keep the output pressure up still)
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Taking a break....teamless for now