Shimano BR-CX77 brake unit. Cable actuated, Dual adjustable pad clearance, For use with Drop-Bar or Flat-Bar road levers, Frame or fork mount (adaptor & rotor not included), Low profile design, 74mm caliper. Info from Shimano web site:

This was taken of the rear of a Specialized Tricross that I switched to hydraulic, but should be usable front or rear. Works just fine.

Currently does not have brake pads installed. For no charge, I can reinstall the used ones from it(not much life left on them). For additional $10, I will throw in new Shimano G02A pads (either installed in the caliper for you, or left in the unopened Shimano packaging).