On Wednesday, January 23, 2019 at 9:30:16 AM UTC-6, Scott Williams wrote:
https://legacy.life-assist.com/Produ...-Cylinders/929
One U.S. option is a Luxfer M15 carbon wrapped oxygen cylinder available from some EMS suppliers, link to one above, comes with a post valve, so you would need an adapter or change the valve to a Sherwood YVBA 5454-xx-75 g.
some of these suppliers require a doctors script.
Good luck,
Scott

One important thing to know about CF O2 cylinders is that they have a limited lifespan of 15 years versus steel and aluminum cylinders which have an unlimited lifespan (according to the Aerox web site).