Shimano Ultegra Di2 E-tube STI Set ST-R8170 Bled Hydraulic Disc - Flat

High performance Ultegra wireless hydraulic servo wave disc brake Di2 sti's give you control, modulation and power with minimal effort in all riding conditionswireless connectivity to the front and rear derailleurs for effortless trouble free gear shiftswith Di2 technology shifting is 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 gearfull 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