From my experience in the States most of their plumbing fittings are our equivalent of 1/4 inch as they fit isolating valves under every tap outlet. I also think you wuill find that our Plumbing fittings are all threaded in BSP and the Americans are all in NPT which is not an easy conversion to couple to.
Selgas Services Ltd Craftsman Gasfitters, Plumbers, Electrical Service Technicians
If that is true why bother buying it everytime you have trouble you will have to contact someone over there, dont buy it. We have some good ones here, maybe you can find one here that looks like the auzie one.