Using these Shimano Dura - Ace R9160 Di2 TT bar end shifters is easy. When you're riding in the aerobars, just use the single - button design to quickly shift the gears. You can program each shifter to upshift or downshift the rear derailleur as you like. The Di2 computer will take care of the front derailleur for the best gear setup. For firmware updates, use Shimano's E - Tube project. Keep the shifters clean and dry. Avoid exposing them to extreme heat or cold. If you notice any issues, check the connections and make sure they're secure. That way, your shifters will keep working well for a long time.