K Tool Flaring kit

I know nothing about them. I would lean more towards something I've heard of. Imperial, is one.

Maybe a better question is, "what are you" trying to flare? IE what kind of tube, and purpose?

Steel brake and cooler lines are 45* double flare

JIC is normally single flare, but frankly, I don't "like" the idea of single flaring something like standard steel brake tube with AN fittings

The double flare is to prevent splitting on the flare end. Especially on something which vibrates, such as I used to work on refrigeration, copper lines, we' run into leaks where some "cheap ***" mechanic had single flared a copper line---and it had split.