Many of our tanks are used in a plethora of industries including medical, racing, Aquacultural, and home brewing. All of our canisters are new with recent hydro test dates on units that allow and require them. A not on all tanks is there are different types of threads depending on the type of compressed gas you put into them. Please takenote as a nitroous oxide NOS tank would have a CGA 580 thread while a co2 tank would have a cga-320 thread.