The Shimano Ultegra 6871 Di2 TT BrakeShift Lever Set enables rapid fire shifting and smooth braking capabilities for time trail and triathlon events. And though it may seem counterintuitive to add a second set of shifters to your time trail or triathlon bike, this brakeshift lever set helps you switch gears and slow down quickly without having to move your hands to the bar ends for shifting and braking duties. The result is less fidgeting at high speeds for increased efficiency and peace of mind.This brakeshift lever set is engineered for bikes with double chainrings. The left brake lever controls the front derailleur, while the right brake lever exerts control over the rear derailleur, ensuring crisp, reliable shifts with your Di2 drivetrain with the press of a button. Moreover, its alloy brake levers are adjustable, allowing you to dial in the perfect reach. Note that this set comes with both right and left braking levers, all the necessary cables, and housing ferrules.