Originally Posted by
Veloh
Goes in the brake lever. They're just a guide. No idea why they don't have it made into the lever body itself.
Bingo. PM'd.
I've got those in my levers - without them you can still use the same levers, but as non-aero. There are tiny little round plugs at the top that plug the top entry cable holes when you've got them set up as aero. So, a dual-purpose lever, can be used for top entry or aero cable routing. A transition part in the evolution of bicycles?