Will this work for CO2?

When I looked at pressurized CO2 before... I got a glimpse of those price tags, let out a sigh, and went right back to my low-tech plans. I never expected to go this far, so I don't know enough to tell if this is suitable.

Here is what I stumbled across... a cylinder with regulator that has been used for oxygen. He says it's it good shape and doesn't leak. He wants $50 for the whole thing.

Would this work okay? Is it too big, too old, the wrong kind? Please let me know...

Thanks!!

And... assuming I actually get this (or different one) someday... where do you stash your cylinders so they're out of view? Tucked discretely behind a ficus tree, or something? (Maybe I should start knitting a cylinder-cozy.)

Thanks, both of you. I figured that would be the case. I had never seen anyone talk about using an O2 tank and switching it over for our purposes.