An ideal upgrade for your road or mountain bike's (MTB's) Shimano electronic drivetrain, the Shimano SM-EWU111 Di2 Wireless Unit fits onto your E-Tube wiring and enables you to pair up your smartphone or tablet to make updates and adjustments. The Shimano EW-WU111 is a Di2 component that allows wire-free communication between your shifters and a compatible smartphone or tablet. This means you no longer need to physically connect your bike to the PCE1 interface to carry out tasks such as updating the system firmware or to customise things such as shifting speed and shifts per click.