Giving you the freedom of light gear changes, this stunning component reduces effort & means that you can focus on the trail. It uses a computer-controlled auto trim as the chain moves up & down your cassette to keep the drivetrain running flawlessly. Furthermore, Shimano's Synchronised Shift compatibility allows a single shifter to control both front & rear shifting for even more precision on every run. Shimano Di 2 MTB Front Mech Keeping you in full control, this model's faster & more accurate shifting performance is noticeable even under load. Di 2 technology removes the traditional cables in favour of electrical cables which not only eliminates poor shifting caused by contaminates, corrosion & stretching, but provides effortless gear shifts no matter what the conditions.