the monospacers are only available through Trek dealers. it's possible a professional fitter might buy them that way to have on hand if they expect a lot of Trek clients. otherwise, I imagine a fitter would be able to determine your needs via some other mechanism (fit bike, size cycle, etc), consult our fit chart, and let yo uknow which monospacer(s) to buy from your Trek dealer.
Carl Matson
Carl Matson