The BCC910 is a single coil floating pickup shaped like an old Charlie Christian. It has adjustable polepieces and a tone quite similar to a P90.
The KCC910 is quite similar, but it doesn’t need a pickguard and so it hasn’t got a tab. It has screws that attach it to a brass piece that is in turn attached to the neck end:
That system works for all neck widths. You won’t have to remove wood from the sides of the neck as for some C-shaped brackets.