I'm seeing it on Amazon too. It looks like there's a copper/nickel alloy and a zinc plated steel version commonly available. The steel looks cheaper and I'd imagine more durable, though probably harder to work with and more corrosion prone. Let me know what you go with. My flaring kit is cheap, but has worked fine for copper tubing in the past. I'm not sure how well steel would work out, so I may lean toward the copper/nickel.
