Inline D-Fly / Wireless Unit
The EW-WU111 D-fly allows your Di2 system to communicate wirelessly with your head unit and smartphone or tablet. It'll let you display currently selected gears, allows you to switch head unit screens, update firmware, change settings and more.
It is generally placed on road bikes, positioned somewhere outside the frame, or in your handlebars. Have a look at the attached user manual for examples on where to place this unit on your bike.
While Shimano officially do not condone placing this inside the frame or handlebars, in most cases that'll work just fine. I personally have never heard of anyone complaning about signal strength due to it being installed inside the frame.
The unit has two e-Tube ports - one on each end - allowing it to be place in between two cables. Note that you do not have to connect both ends. That is completely up to you.
BT-DN110 / BM-DN100 required
The EW-WU111 / EW-WU101 wireless units are meant to be used with the BT-DN110 / BM-DN100 battery/mount and will not work with the older SM-BTR2, SM-BMR1 or SM-BMR2 batteries. The older SM-EWW01 will work with the older batteries, but only supports ANT+ (no BluetoothLE).
Details & Specifications
|Shimano model number:||EW-WU111|
|Component series:||Non-series components NON (All)|
|Downloads:||EW-WU111 User Manual|
EW-WU111 Declaration of Confirmity