This is the shimano dura ace r671 di2 tttriathlon switch set no need for time triallists and triathletes to choose a shifter position with di2 multiple shift controls are possible use dual control levers on the base bars and satellite controls on aero extensions the controls work together shift from base bars or in the aero position instantly multiple control positions mean shifts are always close at hand fast accurate effortless shifts sw 9071 single button controls minimise movem