Let us clarify one thing. These brake levers don't ratchet. They are desiged to let you install IRD's Power Ratchet thumbshifters in front of the lever.
The interface will also work with Rivendell Silver and ENE Ciclo shifters.
Traditional Standard pull levers.
The mount sits above the lever to leave lots of room to wrap your finger around the levers. If you are tired of your STI brake/shifter levers getting banged up or jammed up, give these a try.