Great tool. Easy to use fool proof flares For metric lines only - 3/16 is the same as the 4.75mm, 5mm and 6mm line sizes only. I was looking for a tool that did metric flares but SAE line sizes. Luckily most of the flares I needed to do were 3/16. This set will not do 1/4" or 5/16 or 3/8 lines. Comes with a fairly sturdy plastic case.