Shimano Ultegra ST-R8170 Ultegra hydraulic Di2 STI for drop bar without E-tube wires,.

• High performance Ultegra Wireless hydraulic Servo Wave disc brake Di2 STI's give you control, modulation and power with minimal effort in all riding conditions
• Wireless connectivity to the front and rear derailleurs for effortless trouble free gear shifts
• With 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 gear
• 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 ratio
• Simply pressing tactile buttons allows effortless and comfortable shifting even when your hands are cold
• Drop bar STI with shift buttons located in a near identical place to the positions you'd assume shifting using a mechanical Shimano STI
• Hydraulic brake lever with Servo Wave provides excellent stopping power with less effort especially from the hood position
• Hydraulic reservoir tank provides pad to rotor clearance auto-adjust maintaining braking performance during pad wear
• Finely tuneable reach adjusters for the levers enable custom fitment for all hands
• Levers use CR1632 batteries which last for approximately 1.5-2 years