The brush nib available or the Original is not as long or flexible as the Super Brush nib on the Sketch, but you can still use it for the flicking motion to apply ink. It's actually a nice option for people who need a little more control than they get with the super brush.
I've attached photos of each of the nibs. You will notice that the brush on the Original does not fit in the chisel end, but it fits in the fine tip end.
Copic Original Brush Nib -
HERE
Sketch Super Brush Nib -
HERE
Hope that helps!