william S.wrote a review of Shimano Di2 Inline Wireless Unit - EW-WU111 on May 5, 2019
Familiarity: I've used it several times
Install was very simple. It took less than five minutes to install it under the seatpost of a 2019 Specialized Venge. After install my phone detected it immediately however it failed the firmware update multiple times. I kept getting an error message about unstable wireless connection. I pulled the seatpost and had the unit almost right next to my phone and still got the message. It took a lot of patience to finally get it connected and working. After the update it paired immediately with my Garmin 520. The main reason I wanted it was for using the buttons on my brake hoods for scrolling the Garmin screens. This function was was easy to set-up and has functioned flawlessly. Also allows for easy shift profile changes (I prefer semi-synchronized) and allows monitoring of Di2 battery levels.