Reading the assembly instructions, it says you can be creative with a Sierra tube and cut it, placing the center band wherever you want for that design opportunity. Or, leave it off completely with a Sierra tube cut to fit this kit if needed. That make this a more like a single tube Sierra with textured finial. It's also a finial twist instead of nib twist, more like the aero.
I ordered one the other day after seeing it advertised in Woodturning Design magazine, and it should be here today. Only problem is I won't be here to turn it - long weekend beach trip! Next week I'll get to it, and write up a small review if no one else beats me to it.