Shimano SYSTEM INFORMATION DISPLAY/JUNCTION-A, SC-M9051

The SC-M9051 System Information Display shows you:
-what gear you're in
-has a battery level indicator
-charging port
-synchronized shift mode display
-also doubles as a Junction A - it has 3 e-Tube ports for you to connect components to it.
The displays lets you charge the system and also connect to it using Bluetooth or ANT+.

It supports both 31.8mm and 35mm diameter handlebars.