Bubble Flare

[Kenney Kelley]

I recently bought a tube flaring kit for three different types of tubing flares. I know how to do flares on Copper tubing , Double flares on Brake lines but i've never heard the word Bubble Flare used or where they're used. My question is where are they used? and what kind of tubing are they used on?

Thanks Kenney Kelley