I suspect it is a "leverage ratio converter". But I've seen a tektro mini-v that's cyclocross specific... ie... intended for use with brifters. I can't confirm, but would suspect, that model won't require any adapters.

EDIT: I suspected wrong. I just looked on ebay... the cyclocross ones indicate needing the "travel agents", and I have not the first clue what that could even mean.

Anyone?