ST-R9160, Dura-Ace Di2,For time trial and triathlon use, the DURA ACE ST R9160 levers reduce drag thanks to their aerodynamic design. The one button layout integrates seamlessly with SHIMANO's SYNCHRONIZED SHIFT. BENEFIT Optimum power transmitted with firm grip FEATURE More aerodynamic and better grip feeling TECHNOLOGY Switch button integrated inside without hand release BENEFIT Intuitive shifting control FEATURE Keep firm grip when shifting FEATURE Single button on each