Shimano Dura-Ace Di2 black-R9160 handle bar end switch pair

SEIS SHIMANO ELECTRONIC INTELLIGENT SYSTEM
The current Di2 groups use a technologically innovative, computerized switching system based on the Di2 concept called SEIS (SHIMANO ELECTRONIC INTELLIGENT SYSTEM). The innovative shifting technology of the SEIS continues to be based on the SHIMANO INDEX SYSTEM (SIS), whose outstanding switching performance has proven itself over many years. The main difference between the systems is that the switching process is no longer performed mechanically, but electronically.
This electronic switching system has been extensively tested in recent years by several professional cyclists in all conceivable conditions, z.žBB. in rain, mud, extreme cold, on cobblestones and also in combination of these factors.
The switching process is carried out by simply pressing a button. No effort is required to shift, which brings significant benefits, since the driver always has the handlebars firmly under control and can focus on driving without being distracted by the shift. The shifting system allows precise and effortless shifting in all situations, even with cold hands or when the driver has exhausted completely. The switching power can also be no longer affected by dirty or stretched trains, since the switching signal is transmitted electronically. The control buttons work much like mechanical dual-control levers, making it easy to get used to the SEIS.

E-TUBE
E-TUBE is a system platform for the concept of DI2 (DIGITAL INTEGRATED INTELLIGENCE). E-TUBE transmits interactive signals and supplies power to all electronic parts through "plug & play" connections. E-TUBE is corrosion, strain and frost resistant and ensures low maintenance. It offers optimal flexibility for your bike. With E-TUBE Project you can customize the settings of electronic components and update the firmware via Windows PC or tablet or smartphone. It provides quick and easy access to information about electronic components and provides an instant overview of system status.