the hydro date is when you are suppose to test it, take it to your local paintball shop and they will send it in to be tested.
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Black/Blue fade PM5
new designz venom trigger
Ultralite barrel
virtue board
cp asa
Hyper2 reg yeah it is an upgrade
clamping feedneck Rate my Proto M5
if you're a christian paintballer put this in your sig.
They pump it up to a certain PSI for a certain time and if it doesn't blow up it's good. Visual inspection also. A dive shop can probably do it for you on site also.