This is the Shimano Ultegra FD-6800 Front Derailleur. The Ultegra series is "pro-proven" as it is a direct trickle down from the Dura Ace group. It stands for state-of-the-art technology, proven in pro races, the technology used in the new Ultegra 6800 series with 11 speed, improved design brakes, improved chain treatment and all the same technologies you have come to expect from Shimano's engineers.
With a revised actuation ratio in combination with the ST-6800 shifter and polymer-coated cables, the new Ultegra front derailleur delivers both a shorter stroke at the lever and reduced effort
Next generation light effort front shifting, optimum spring tension provides feather-light down shift
New designed pull arm for more direct and easy shifting
More equal shifting effort across the range
New support bolt for more stable contact to the frame