Shimano Dura-Ace Di2 FD-R9150 Front Derailleur 2x11-speed Braze-On black

The new Dura Ace from Shimano is the answer to the question of many profs and ambitious amateurs as to whether and how the current high level of performance could be further increased. Each individual Dura Ace R9150 component is designed to work as efficiently as possible with all other components of the system. This shows the core of Shimano's component-developed-as-a-system philosophy particularly clearly. The result is called SYSTEM SUPREMACY - the superiority of the system over the sum of the individual parts.The new Dura Ace Di2 front derailleur comes with a fundamental design change, several cable control options and integrated tension adjustment. The low-profile design provides a slim appearance while improving the ability to withstand damage from falls.

SEIS SHIMANO ELECTRONIC INTELLIGENT SYSTEM
A technological innovation of the computerized shifting system based on the DI2 concept with which is called, the SEIS (SHIMANO ELECTRONIC INTELLIGENT SYSTEM). The SEIS innovative shift technology is still based on the SHIMANO INDEX SYSTEM (SIS) that has proved its superior gear changing characteristics over the years. The big difference is that in this case, the shifting action is provided for by electronics instead of mechanics. This electronic shifting system has been extensively tested over past two years by several professional riders in all conditions possible, such as rain, mud, low temperatures, cobble stone roads and combinations of all of these at the same time. Shifting is executed by simply pressing the button. No power is needed to shift, which gives important advantages since it is easier now to always keep a tight grip on the handlebar and to keep your concentration on riding instead on shifting. The shift system allows accurate and effortless shifting in difficult circumstances for example when you have cold hands or when you are completely exhausted. Furthermore, the shifting performance will never be affected by contaminated or stretched cables since the shifting signal is transferred electronically. The operating buttons work similarly to mechanical DUAL CONTROL LEVER so you don’t need to re-program your mind for the SEIS.