See picture and description in attached. http://urbanvelo.org/issue13/urbanvelo13_p82-83.html. Brake housing is on right, shifter on left. Brake housing is continupous spiral' Shifter is a bunch of wire strands running same direction as the outside cover. You can use brake housing for shifters (although shifting won't be as good because housing compresses slightly). You can't use shifter housing for brakes because it will rupture under the load that braking puts on housing.