Tektro RX 2.1 Cross Top or Interrupter Brake Levers 31.8mm Clamp Silver - Pair

These mount on drop bars right where the stem clamps, this means you can operate your brakes while riding on the tops of your bars. 

These can be used either by themselves, or as interrupter levers for brifters or other drop bar levers. 

Short-pull levers, compatible with road caliper, cantilevers, mini v, and short-pull "road" mechanical disc brakes. 

31.8mm hinged clamp fits modern, oversize bars at the stem. Adjustable reach plus return spring.