Very small transmitter from Shimano that can put between any two wires on the system and send data to and from other devices via Bluetooth.

Can be used with a cycling computer to display "real-time" data such as which gear you are in or can be used with Shimano's E-tube app to set and program your DI2 setup.

Important! This is the latest version Shimano D-Fly. It is exclusively compatible with Shimano's new BT-DN1110 battery.