This is the charger cable for Shimano's Di2 SM-BCR1 Battery Charger. And if you're running Dura-Ace or Ultegra electronic shifters and derailleurs, then this is an important piece of the puzzle. The charger does NOT come with a cable. If you're paying attention, you'll see that the cable and charger are the same for both Dura-Ace and Ultegra systems, as is the battery.

• A wire