In-line Forte (Perfornance Bike) 31.6 or 26.0mm (shims) Cyclocross lever (right side lever).
I bought the pair new and used the left side for fixed gear bike with front brake only build. This lever can go in-line or stand alone as a single brake lever. Perfect for fixed gear bike. You'll have to want your lever mounted on the right or run it up-side down for left.
This is a nice part. Add $1.80 to ship to U.S. 48 states.