Patp, yes, I have experience with the SCBA tanks on eBay, but not the AliExpress or Chinese non DOT tanks. The ones from China, both AliExpress and eBay are CE certified. Unfortunately, most Dive or Paintball shops in the USA will not fill them. So if you have your own compressor, then its a possible good deal. If not, then not so much. You can buy a good used SCBA tank with a few years of service left for under $150. And then a fill rig from eBay for about $50 or so. The service life on all the carbon fiber tanks is 15 years, with a hydro required every 5 years.