Brake levers?

Aye, that's the sort. Maybe I'm wrong but with this set-up the cable itself doesn't get pulled - correct? So is the braking affected by the pushing down of the cable housing on the caliper? If this is the case, am I right in thinking the length of the cable housing has to be very accurate? And do I need a certain type of very rigid cable housing??
Thanks for answering, Hippy.

Yep
Not really. Braking is probably not as good as a nice drop lever but it can certainly lock the wheel and modulation is good enough for me.
Not very accurate - long enough to allow it to reach the calipers but not too long so as to be flopping all over the place.
Nope. Standard cable, standard cable outer.