The Shimano ST-R8150 Ultegra Shift and Brake Lever with Di2 technology, makes shifting easy and precise - just a light touch, as soft as a mouse click, is sufficient for the front or rear derailleur to instantaneously select the correct gear. Servo Wave brake lever pivot is positioned to be used with super SLR brake callipers, increase power providing excellent ergonomics when riding on the hoods.Full and semi synchronized shifting programable, Synchro shift compatible meaning a single shifter can control both front and rear shifting which can be fully custom tuned to your riding preferences. Semi synchronized shifting means when a front shift is made the rear mech will automatically correct to the appropriate ratioSimply pressing tactile buttons allows effortless and comfortable shifting even when your hands are coldDrop bar STI with shift buttons located in a near identical place to the positions you'd assume shifting using a mechanical Shimano STIServo Wave brake lever pivot is posi