I just had one given to me by a buddy of mine, and it's about 2 yrs old. I pulled it out and it appears to be O.k, but there is a little corrosion on the CO2 itself. How long can you go until you must change the charge out. I gave the preserver a test, and its still in good shape, I just worry that the CO2 will not go off if in need. Its the type that goes aroud your waist inside of a little pouch, the rip cord just hangs out of the side for easy acess. Thank You Guys For All Your Help. This Is An Awesome Site, And Club U Have here. Glad I could Join Ya!!