Also look at the very similar tool made/sold by
http://www.sykes-pickavant.com/ on the right side of the page in the bottom left of the picture, otherwise open their brake and suspension catalog
http://www.sptools.co.uk/Catalogue/tabid/104/Default.aspx.The '270' series brake pipe flaring tools
Part number 02700000 is probably the best choice, covers 3/16"-3/8" double flares.
I think Sykes-Pickavant makes the Fedhill tool, and apparently their own of very similar if not better design (many of the same parts between the two of them).