Buffer for BCM 12.5 KINO Middy

I have a BCM 12.5 KINO mid-length that I use a Surefire FA556 can on. Should I be using the H buffer?

And as a sidenote it seems that the H buffer is recommended for most builds is this correct? When wouldn’t I want an H buffer?

The 12.5" Kino configuration has a carbine length gas system with a FSB set at mid-length distance. If you are running a BCM, try the H buffer or H2.