SHIMANO EW-SD50 E-TUBE DI2 ELECTRIC WIRE 

For the rider using and setting up their own Di2 groupset, making sure that you've got all the cabling at hand and in the right lengths is a critical concern. With the Shimano EW-SD50 E-tube Di2 Electric Wire, you can make sure to connect up the dots in your electronic groupset and make sure that your junction box is communicating with the rest of the components on your bike.

This cable transmits electronically, meaning that all your shifting information is carried out accurately, rather than relying on typically stretchy wires.